Leek and Smoked Potato Gratin with Gruyère
A comforting Flemish comfort food featuring creamy leeks and potatoes baked in a rich cheese sauce with a golden crust, perfect with a simple green salad. This belgian-inspired vegetarian ready in about 75 minutes pairs medium, thinly sliced russet potatoes, unsalted butter, all-purpose flour for a weeknight-friendly dinner that comes together with one pan and minimal cleanup. Each serving lands at about 380 calories and feeds 6, so it slots cleanly into a weekly meal plan and pairs well with a quick salad or grain on the side. Tap "Plan a meal with the AI" below to drop this recipe into your week and send the ingredients straight to Instacart. Nutrition values are approximate, calculated from USDA FoodData Central (fdc.nal.usda.gov) — verify against ingredient labels for any health-driven dietary plan.
Ingredients
- 3, white and light green parts, thinly sliced small leeks
- 2 medium, thinly sliced russet potatoes
- 4 tbsp unsalted butter
- 3 tbsp all-purpose flour
- 2 cups whole milk
- 1 cup, grated Gruyère cheese
- 1 tsp smoked paprika
- 1 tbsp, chopped fresh thyme
- 1 tsp salt
- 1/2 tsp freshly ground black pepper
Equipment for this recipe
Top-rated tools to make this recipe successfully.
Instructions
- Step 1: Preheat oven to 375°F (190°C). Butter a 9x13-inch baking dish.
- Step 2: Melt 2 tbsp butter in a medium saucepan over medium heat. Whisk in flour and cook for 1 minute until golden. Gradually whisk in milk, stirring constantly until thickened (about 5 minutes).
- Step 3: Remove from heat. Stir in 1/2 cup Gruyère, smoked paprika, thyme, salt, and pepper until melted. Set aside.
- Step 4: Layer half the potatoes and half the leeks in the baking dish. Pour half the cheese sauce over them. Repeat layers with remaining potatoes and leeks.
- Step 5: Pour remaining cheese sauce evenly over the top. Sprinkle with remaining 1/2 cup grated Gruyère.
- Step 6: Bake uncovered for 45-50 minutes until golden brown and bubbly around the edges. Let rest for 10 minutes before serving.
Frequently asked questions
How long does Leek and Smoked Potato Gratin with Gruyère take to make?
Total time is about 75 minutes (25 min prep + 50 min cook). Most home cooks find this fits comfortably into a weeknight; double the batch on Sunday for two dinners.
How do I store leftover Leek and Smoked Potato Gratin with Gruyère?
Cool to room temperature within 2 hours, then store in an airtight container in the fridge for up to 4 days. Reheat covered in a 350°F oven for 10-12 minutes, or microwave at 70% power in 60-second bursts to keep unsalted butter from drying out.
Can I substitute ingredients in Leek and Smoked Potato Gratin with Gruyère?
Yes — most ingredients in this recipe have flexible swaps. For oil, use any neutral high-smoke-point oil (avocado, grapeseed, refined coconut). For aromatics, dried herbs at ⅓ the volume of fresh work in a pinch. The full ingredient list is shoppable on Instacart so you can see substitutes in real time.
How do I scale Leek and Smoked Potato Gratin with Gruyère for a different number of people?
The recipe is written for 6 servings. Multiply each ingredient by (your serving target / 6). Cook time stays roughly the same up to 2x; for 3-4x batches, switch from a skillet to a sheet pan or stockpot so the food isn't crowded — overcrowding steams instead of browns.
What goes well with Leek and Smoked Potato Gratin with Gruyère?
Belgian vegetarian like this pair well with a simple grain (rice, couscous, or crusty bread), a quick salad with acid (lemon vinaigrette, pickled onions), and a pan sauce or yogurt-based dip. Tap "Plan a meal with the AI" to get specific side suggestions.
What others are saying
- ★★★★★
Made with what I had on hand and it still came out great.
- ★★★★☆
My family liked it. I personally would prefer more depth of flavor.
- ★★★★☆
Solid recipe. Not groundbreaking but definitely making it again.
