Quick Recipe Version (TL;DR)
Quick Ingredients
- 6 round zucchini (zapallitos), about 3–3.5 in wide (approx. 2.5 lb/1.1 kg total)
- 2 tbsp olive oil
- 1 large onion, finely diced
- 3 garlic cloves, minced
- 1 lb (450 g) ground beef (85–90% lean)
- 1 cup (240 ml) crushed tomatoes
- 1 tbsp tomato paste
- 1 tsp sweet paprika, 1/2 tsp cumin, 1 tsp dried oregano
- 1/2 tsp black pepper, 1 tsp kosher salt (plus more for blanching)
- 1/2 cup cooked white rice (or 1/2 cup fresh breadcrumbs)
- 1/4 cup chopped fresh parsley
- 4 oz (115 g) shredded mozzarella or provolone + 1/4 cup grated Parmesan
- 1/4 cup water or broth (for baking dish)
Do This
- 1. Heat oven to 375°F (190°C). Slice caps off squash; hollow with a spoon, leaving 1/4 in (6 mm) walls. Chop 1 cup of the pulp.
- 2. Blanch shells and caps 4 minutes in salted boiling water; drain upside-down 5 minutes.
- 3. Sauté onion in olive oil 5 minutes; add garlic 30 seconds. Add beef; cook until browned, 5–6 minutes.
- 4. Stir in chopped squash pulp, spices, salt, pepper, crushed tomatoes, and tomato paste. Simmer 6–8 minutes to thicken.
- 5. Off heat, mix in rice or breadcrumbs and parsley. Pack squash with filling; top with cheeses. Arrange in baking dish with 1/4 cup water/broth.
- 6. Bake 25–30 minutes until bubbling; broil 2–3 minutes to brown. Rest 5 minutes, then serve.
Why You’ll Love This Recipe
- Comforting Argentine-style flavors: savory beef, onion, tomato, and gentle spices.
- Perfect make-ahead: the filling can be prepared up to 2 days in advance.
- Flexible binder: use cooked rice for tenderness or breadcrumbs for a heartier bite.
- Crowd-pleaser presentation: golden, cheesy tops and cute “cap” lids.
Grocery List
- Produce: 6 round zucchini (zapallitos), 1 large onion, 3 garlic cloves, fresh parsley
- Dairy: Shredded mozzarella or provolone, grated Parmesan
- Pantry: Olive oil, crushed tomatoes, tomato paste, white rice or fresh breadcrumbs, kosher salt, black pepper, sweet paprika, ground cumin, dried oregano, broth (optional)
Full Ingredients
For the Squash
- 6 round zucchini (zapallitos), 3–3.5 inches (7.5–9 cm) diameter
- Kosher salt, for blanching water (1 tablespoon per 4 quarts/3.8 L water)
Beef–Tomato Filling
- 2 tablespoons olive oil
- 1 large yellow onion (about 8 oz/225 g), finely diced
- 3 garlic cloves, minced
- 1 pound (450 g) ground beef, 85–90% lean
- 1 cup (240 ml) crushed tomatoes
- 1 tablespoon tomato paste
- 1 teaspoon sweet paprika
- 1/2 teaspoon ground cumin
- 1 teaspoon dried oregano
- 3/4 to 1 teaspoon kosher salt, to taste
- 1/2 teaspoon freshly ground black pepper
- 1 cup chopped reserved squash pulp (from hollowing)
- EITHER 1/2 cup cooked white rice (about 80 g cooked) OR 1/2 cup fresh breadcrumbs (about 30 g)
- 1/4 cup (10 g) chopped fresh parsley
- Optional: 1 large egg, lightly beaten (for extra binding)
For Topping & Baking
- 4 ounces (115 g) shredded mozzarella or provolone
- 1/4 cup (25 g) finely grated Parmesan
- 1/4 cup (60 ml) water or low-sodium broth, for the baking dish
Step-by-Step Instructions
Step 1: Prep and hollow the squash
Preheat the oven to 375°F (190°C). Using a sharp knife, slice off a 1/2-inch (1.25 cm) “cap” from the top of each round zucchini. With a teaspoon or melon baller, carefully scoop out the interior, leaving 1/4-inch (6 mm) thick walls and base. Reserve and finely chop 1 cup of the scooped pulp for the filling. Lightly season the insides with a pinch of salt.
Step 2: Par-cook the shells
Bring a large pot of salted water to a boil (1 tablespoon kosher salt per 4 quarts/3.8 L). Add the hollowed shells and their caps; simmer for 4 minutes to soften slightly. Drain thoroughly, placing shells upside down on a towel-lined tray for 5 minutes so excess moisture escapes. This prevents watery filling later.
Step 3: Build the beef–tomato base
Heat the olive oil in a large skillet over medium heat. Sauté the onion for 5 minutes until translucent. Add the garlic and cook 30 seconds until fragrant. Add the ground beef; cook, breaking it up, until no pink remains and lightly browned, 5–6 minutes. Spoon off excess fat if needed. Stir in the chopped squash pulp, paprika, cumin, oregano, salt, and pepper. Cook 2 minutes to soften the pulp.
Add the crushed tomatoes and tomato paste. Simmer, stirring occasionally, until thick and saucy but not wet, 6–8 minutes. You want a spoonable filling that holds its shape.
Step 4: Add binder and herbs
Remove the skillet from heat. Stir in the cooked rice or fresh breadcrumbs and the parsley. Taste and adjust salt and pepper. Let the mixture cool for 5 minutes (so the cheese won’t melt prematurely); if using, stir in the beaten egg.
Step 5: Stuff and top with cheese
Arrange the drained squash shells upright in a snug baking dish. Spoon the filling into each, packing lightly and mounding just above the rim. Sprinkle generously with the shredded mozzarella or provolone, then dust with Parmesan. Nestle the squash caps on top or lean them slightly to one side. Pour 1/4 cup (60 ml) water or broth into the baking dish to create gentle steam.
Step 6: Bake until bubbling and golden
Bake at 375°F (190°C) for 25–30 minutes, until the cheese is melted and the filling is hot in the center (165°F/74°C). For deeper browning, switch to broil for 2–3 minutes, watching closely so the tops don’t burn.
Step 7: Rest, garnish, and serve
Let the zapallitos rest for 5 minutes to set the juices. Garnish with extra parsley if you like. Serve warm with a simple salad or crusty bread to soak up the savory juices.
Pro Tips
- Drain shells upside down after blanching to avoid soggy bottoms and watery filling.
- Cook the filling until thick; excess moisture will dilute flavor and collapse the squash.
- Rice yields a softer, classic texture; breadcrumbs create a firmer, meatball-like bite.
- Pack the filling gently—overpacking can split the shells as they bake.
- Use a mix of mozzarella (melt) and Parmesan (savory tang) for the best cheesy top.
Variations
- Porteño-Style: Fold in 1 hard-boiled egg (chopped) and 2 tablespoons chopped green olives for a traditional Buenos Aires touch.
- Vegetarian: Swap beef for 12 oz (340 g) finely chopped mushrooms sautéed until dry, plus 1 cup cooked lentils.
- Spicy Chorizo: Replace half the beef with fresh chorizo (casing removed), and add a pinch of red pepper flakes.
Storage & Make-Ahead
Filling can be made up to 2 days ahead; store covered in the refrigerator. Stuffed, unbaked squash keep well for 24 hours—cover tightly and refrigerate, then bake as directed, adding a few extra minutes. Leftovers: refrigerate up to 3 days or freeze up to 2 months (wrap individually). Reheat covered at 350°F (175°C) for 18–22 minutes from chilled, or 30–35 minutes from frozen, until hot throughout.
Nutrition (per serving)
Approximate for 1 stuffed squash (1 of 6): 360 calories; 23 g protein; 21 g fat; 16 g carbohydrates; 3 g fiber; 640 mg sodium. Values will vary with rice vs. breadcrumbs and cheese choices.
