Roast Beef Bagel With Caramelized Garlic Aioli

Quick Recipe Version (TL;DR)

• Yield: 4 bagel sandwiches
• Prep Time: 20 minutes
• Cook Time: 40 minutes
• Total Time: 60 minutes

Quick Ingredients

• 4 onion bagels, split
• 12 oz thinly sliced roast beef
• 2 cups loosely packed baby arugula
• 4 small shallots, thinly sliced
• 1 whole head garlic
• 1 cup mayonnaise
• 2 tsp Dijon mustard
• 1 tbsp fresh lemon juice
• 1/4 cup extra-virgin olive oil, divided
• 1/3 cup white wine vinegar (or apple cider vinegar)
• 1 tbsp granulated sugar
• 1 1/4 tsp fine sea salt, divided
• 1/2 tsp freshly ground black pepper

Do This

• 1. Heat oven to 400°F (200°C). Slice top off garlic head, drizzle with 1 tbsp olive oil and a pinch of salt, wrap in foil, and roast 35–40 minutes until deep golden and very soft.
• 2. While garlic roasts, thinly slice shallots and place in a jar with vinegar, sugar, 1/4 tsp salt, and 2 tbsp warm water. Stir and let sit at least 20 minutes.
• 3. Squeeze roasted garlic cloves into a bowl. Mash with mayonnaise, Dijon, lemon juice, 2 tbsp olive oil, remaining 1 tsp salt, and black pepper until smooth. Adjust seasoning to taste.
• 4. Toast onion bagels until crisp and golden on the cut sides.
• 5. Spread a generous layer of caramelized garlic aioli on both cut sides of each bagel.
• 6. Layer bottom halves with roast beef, a handful of arugula, and plenty of drained pickled shallots. Cap with bagel tops, slice in half if desired, and serve.

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Why You’ll Love This Recipe

• Layers of flavor: savory roast beef, sweet-caramelized garlic, tangy pickled shallots, and peppery arugula in every bite.
• The onion bagel adds extra toasty, allium flavor that ties everything together.
• Make-ahead friendly: the aioli and pickled shallots keep well, so assembly is fast when you are ready to eat.
• Feels like a gourmet deli sandwich, but is easy and very doable in a home kitchen.

Grocery List

• Produce: 1 head garlic, 4 small shallots, 2 cups baby arugula, 1 lemon
• Dairy: None required (use mayonnaise from pantry)
• Pantry: 4 onion bagels, 12 oz thinly sliced roast beef, mayonnaise, Dijon mustard, extra-virgin olive oil, white wine or apple cider vinegar, granulated sugar, fine sea salt, black pepper

Full Ingredients

Caramelized Garlic Aioli

• 1 whole head garlic
• 3 tbsp extra-virgin olive oil, divided
• 1 cup mayonnaise
• 2 tsp Dijon mustard
• 1 tbsp fresh lemon juice
• 1 tsp fine sea salt (plus a pinch for roasting the garlic)
• 1/2 tsp freshly ground black pepper

Quick Pickled Shallots

• 4 small shallots (or 2 large), thinly sliced into rings
• 1/3 cup white wine vinegar (or apple cider vinegar)
• 1 tbsp granulated sugar
• 1/4 tsp fine sea salt
• 2 tbsp warm water

For the Bagel Sandwiches

• 4 onion bagels, split horizontally
• 12 oz thinly sliced roast beef (about 3 oz per sandwich)
• 2 cups loosely packed baby arugula
• Freshly ground black pepper, for finishing (optional)

Step-by-Step Instructions

Step 1: Roast the garlic until caramelized and sweet

Preheat your oven to 400°F (200°C). Peel off the loose outer papery layers of the garlic head, leaving the cloves still attached. Slice about 1/4 inch off the top of the head to expose the tops of the cloves. Place the garlic on a piece of foil, cut-side up. Drizzle with 1 tablespoon of the olive oil and sprinkle with a small pinch of salt. Wrap tightly in the foil and set on a baking sheet to catch any drips. Roast for 35–40 minutes, until the cloves are deep golden, very soft, and smell sweet and nutty. If they are still pale after 30 minutes, continue roasting in 5-minute increments.

Step 2: Make the quick pickled shallots

While the garlic roasts, prepare the pickled shallots. Thinly slice the shallots into rings and place them in a small heat-safe jar or bowl. In a separate small bowl, whisk together the vinegar, sugar, salt, and warm water until the sugar dissolves. Pour this mixture over the shallots, pressing them down so they are mostly submerged. Let them sit at room temperature for at least 20 minutes; they will turn a lovely pink and become sweet-tangy. For a stronger flavor, let them sit 30–60 minutes. Stir occasionally to ensure even pickling.

Step 3: Blend the caramelized garlic aioli

When the garlic is done, let it cool just until it is comfortable to handle. Unwrap the foil and squeeze the cloves from the base; the soft, caramelized garlic should easily squish out like a paste. Add all the roasted garlic to a medium bowl. Mash it with a fork until mostly smooth. Add the mayonnaise, Dijon mustard, lemon juice, remaining 2 tablespoons olive oil, 1 teaspoon salt, and 1/2 teaspoon black pepper. Whisk or stir vigorously until creamy and well combined. Taste and adjust: add a bit more lemon for brightness, salt for savoriness, or pepper for a gentle kick. Set aside. The aioli will thicken slightly as it stands.

Step 4: Prep the greens and drain the shallots

Rinse and dry the baby arugula thoroughly; excess moisture can make the sandwich soggy. A salad spinner or patting gently with a clean kitchen towel works well. After the shallots have pickled for at least 20 minutes, use a fork or tongs to lift them out of the brine and transfer to a small plate or bowl, shaking off excess liquid. Reserve the brine if you like; it makes a nice quick splash for salads.

Step 5: Toast the onion bagels

Split the onion bagels horizontally. Toast them cut-side up until golden and slightly crisp. You can use a toaster, a toaster oven, or place them cut-side down in a dry skillet over medium heat for 2–3 minutes. Light toasting adds texture and warmth, and wakes up the flavor of the onion topping so it stands up to the rich beef and garlicky aioli.

Step 6: Assemble the roast beef bagel sandwiches

Spread a generous layer of caramelized garlic aioli on both the top and bottom cut sides of each toasted bagel. On the bottom halves, arrange about 3 ounces of roast beef per bagel, loosely folding the slices to create a bit of height and texture instead of laying them flat. Top the beef with a small handful of arugula on each sandwich. Scatter a generous spoonful of drained pickled shallots over the arugula for a bright pop of color and flavor. If desired, finish with a light grind of black pepper.

Step 7: Serve and enjoy

Cap each sandwich with its bagel top, gently pressing down so the layers nestle together but still look tall and inviting. If serving immediately, you can slice each sandwich in half with a sharp serrated knife for easier eating and a beautiful cross-section showing the roast beef, green arugula, and rosy shallots. Serve warm or at room temperature. Any extra aioli or pickled shallots can be served on the side for dipping or spooning over each bite.

Pro Tips

• For deeper garlic flavor, let the roasted garlic cool completely before mixing; the flavors bloom as it rests.
• Use good-quality, fairly thinly sliced roast beef for the best texture; loosely folded layers make the sandwich feel more luxurious.
• Do not skip draining the pickled shallots well; too much brine will make the bagel soggy.
• If your aioli seems too thick, whisk in 1–2 teaspoons of warm water to loosen it to a spreadable, silky consistency.
• To warm a crowd’s worth of sandwiches, assemble them, wrap loosely in foil, and warm in a 300°F (150°C) oven for 8–10 minutes just before serving.

Variations

• Cheesy version: Add a slice of sharp provolone or Swiss cheese on top of the roast beef and briefly broil the open-faced bagels until the cheese melts before adding arugula and shallots.
• Horseradish kick: Stir 1–2 teaspoons prepared horseradish into the caramelized garlic aioli for a spicier, steakhouse-style flavor.
• Turkey twist: Swap the roast beef for smoked turkey and use a plain or everything bagel for a lighter, but still deeply flavorful, sandwich.

Storage & Make-Ahead

The caramelized garlic aioli can be prepared up to 3 days in advance. Store it in an airtight container in the refrigerator. The quick pickled shallots actually get better with time and will keep, covered and refrigerated in their brine, for up to 1 week. For the best texture, assemble the sandwiches just before serving; once assembled, they are best eaten within 1–2 hours. If you need to transport them, wrap each sandwich tightly in parchment or foil and keep chilled until serving, allowing them to come slightly toward room temperature for 10–15 minutes before eating.

Nutrition (per serving)

Approximate per sandwich (1 onion bagel, 3 oz roast beef, about 3 tbsp aioli, arugula, and pickled shallots): 650–700 calories; 32–38 g fat; 55–60 g carbohydrates; 4–5 g fiber; 25–30 g protein; 1,000–1,200 mg sodium. Actual values will vary based on specific brands and exact portion sizes.