German Ham and Gouda Potato Casserole

Quick Recipe Version (TL;DR)

• Yield: 6 servings
• Prep Time: 25 minutes
• Cook Time: 60 minutes
• Total Time: 1 hour 35 minutes (includes 10-minute rest)

Quick Ingredients

• 2.2 lb (1 kg) waxy potatoes, sliced 1/8 in (3 mm)
• 2 medium yellow onions, thinly sliced
• 8 oz (225 g) cooked ham, diced
• 8 oz (225 g) Gouda, coarsely grated (reserve 1/2 cup for topping)
• 1 1/2 cups (360 ml) whole milk
• 3/4 cup (180 ml) heavy cream
• 2 large eggs
• 1 tbsp (15 g) Dijon mustard
• 1 tsp fine sea salt (for custard) + salt for boiling water
• 1/2 tsp black pepper, 1/4 tsp nutmeg
• 2 cloves garlic, minced; 2 tsp fresh thyme leaves
• 1 tbsp (14 g) butter for pan + 1 tbsp (14 g) butter and 1 tbsp (15 ml) olive oil for sauté
• Chives or parsley, for garnish

Do This

• 1. Heat oven to 375°F (190°C). Butter a 9×13 in (23×33 cm) baking dish. Bring a large pot of salted water to a boil.
• 2. Boil sliced potatoes 8–10 min until just tender; drain and let steam-dry 5 min.
• 3. Sauté onions in olive oil and butter 8–10 min until golden; add ham, garlic, and thyme 2 min more.
• 4. Whisk milk, cream, eggs, Dijon, 1 tsp salt, pepper, and nutmeg.
• 5. Layer half the potatoes, half the onion-ham mix, and 3/4 of the layering cheese; repeat. Pour custard over.
• 6. Top with reserved 1/2 cup Gouda. Cover with foil; bake 20 min. Uncover and bake 18–22 min more until bubbling and golden; broil 1–2 min if desired.
• 7. Rest 10 min; garnish with chives and serve.

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Why You’ll Love This Recipe

• Classic German comfort: tender potatoes, sweet onions, and savory ham under a golden Gouda crust.
• Reliable and weeknight-friendly: parboiled potatoes bake evenly and never turn watery.
• Balanced flavor: a creamy custard with Dijon, thyme, and nutmeg keeps it rich but not heavy.
• Great for gatherings: bakes in one dish and holds beautifully for serving.

Grocery List

• Produce: 2.2 lb waxy potatoes, 2 yellow onions, 2 garlic cloves, fresh thyme, chives or parsley
• Dairy: Gouda cheese, whole milk, heavy cream, unsalted butter, eggs
• Pantry: Cooked ham, Dijon mustard, olive oil, fine sea salt, black pepper, ground nutmeg

Full Ingredients

Potatoes and Fillings

• 2.2 lb (1 kg) waxy potatoes (e.g., Yukon Gold), peeled if desired, sliced 1/8 in (3 mm)
• 2 medium yellow onions (about 14 oz / 400 g), thinly sliced
• 8 oz (225 g) cooked ham, diced 1/2 in (1 cm)
• 2 cloves garlic, minced
• 2 tsp fresh thyme leaves (or 1/2 tsp dried thyme)
• 1 tbsp (15 ml) olive oil
• 1 tbsp (14 g) unsalted butter

Custard and Cheese

• 1 1/2 cups (360 ml) whole milk
• 3/4 cup (180 ml) heavy cream
• 2 large eggs
• 1 tbsp (15 g) Dijon mustard
• 1 tsp fine sea salt (plus more for the potato water)
• 1/2 tsp freshly ground black pepper
• 1/4 tsp ground nutmeg
• 8 oz (225 g) young Gouda, coarsely grated (about 2 cups). Reserve 1/2 cup (about 2 oz / 55 g) for topping; use 1 1/2 cups (about 6 oz / 170 g) for layering.
• Optional: 1/4–1/2 tsp lightly crushed caraway seeds (for a classic German note)

For the Pan and Finish

• 1 tbsp (14 g) unsalted butter, for greasing the dish
• 1 tbsp (15 g) chopped fresh chives or parsley, for garnish

Step-by-Step Instructions

Step 1: Heat the oven and prepare the dish

Preheat the oven to 375°F (190°C) with a rack in the middle. Generously butter a 9×13 in (23×33 cm) baking dish with 1 tbsp butter. Set a large pot of well-salted water (about 2 teaspoons fine salt per 3 quarts/3 liters) over high heat to come to a boil.

Step 2: Slice and parboil the potatoes

Slice potatoes to 1/8 in (3 mm) thickness for even cooking. Add to the boiling water and cook for 8–10 minutes until just tender when pierced but not falling apart. Drain thoroughly, then spread the slices on a clean towel or baking sheet to steam-dry for 5 minutes. This prevents a watery casserole.

Step 3: Sauté onions and ham

While the potatoes drain, heat olive oil and 1 tbsp butter in a large skillet over medium heat. Add the onions and a pinch of salt. Cook, stirring occasionally, until soft and lightly golden, 8–10 minutes. Stir in the ham, garlic, and thyme and cook 1–2 minutes more until fragrant. Remove from heat.

Step 4: Whisk the custard

In a bowl or large measuring jug, whisk together milk, cream, eggs, Dijon mustard, 1 tsp fine sea salt, pepper, and nutmeg (add caraway if using). Whisk until smooth and evenly combined. Reserve 1/2 cup (about 2 oz / 55 g) Gouda for the topping; keep the remaining 1 1/2 cups (about 6 oz / 170 g) for layering.

Step 5: Layer the casserole

Arrange half the potato slices in the prepared dish, slightly overlapping. Season lightly with a pinch of salt and pepper. Spoon over half of the onion-ham mixture. Scatter with half of the layering Gouda. Repeat with remaining potatoes, onion-ham, and the rest of the layering Gouda. Pour the custard evenly over the top, tilting or gently shaking the dish to distribute.

Step 6: Bake until bubbling and golden

Cover tightly with foil and bake for 20 minutes. Remove the foil, sprinkle on the reserved 1/2 cup Gouda, and continue baking 18–22 minutes until the top is deep golden, the edges are bubbling, and a knife slides through the potatoes with little resistance. For extra color, broil 1–2 minutes, watching closely.

Step 7: Rest and serve

Let the casserole rest for 10 minutes to set the custard and make clean slices. Shower with chopped chives or parsley and serve warm. A simple green salad or steamed green beans makes a perfect side.

Pro Tips

• Use waxy potatoes (Yukon Gold, Red Bliss) so slices hold their shape and the texture stays creamy.
• Steam-dry the potatoes after draining to avoid excess moisture that can dilute the custard.
• Salt in layers: the water, the custard, and a light sprinkle over potatoes ensure depth without oversalting.
• Shred Gouda on the coarse side of a grater for better melting and those classic golden bubbles.
• Resting 10 minutes is essential for clean slices and a custard that doesn’t run.

Variations

• Bavarian-style: Swap ham for smoky speck or bacon; add 1/2 tsp caraway seeds and a splash (1 tsp) apple cider vinegar to the onions for tang.
• Vegetarian forest mushroom: Replace ham with 8 oz (225 g) sliced cremini or chanterelles; sauté with the onions until browned.
• Lighter comfort: Use 2 cups (480 ml) 2% milk and skip the cream; add an extra egg to help set. Expect a slightly less rich texture.

Storage & Make-Ahead

Refrigerate leftovers, tightly covered, for 3–4 days. Reheat covered at 350°F (175°C) for 20–25 minutes, or microwave individual portions. To make ahead, assemble through Step 5, cover, and refrigerate up to 24 hours; bake straight from the fridge, adding 10–15 minutes to the oven time. Freezing is possible (up to 2 months), though potatoes soften slightly: cool completely, wrap well, thaw overnight, then reheat covered at 350°F (175°C) with a splash of milk or cream.

Nutrition (per serving)

Approximate: 560 calories; 22 g protein; 33 g fat; 43 g carbohydrates; 2 g fiber; 980 mg sodium. Values will vary with specific ingredients and brands.