One-Skillet Butternut Sage Lasagna with Brown Butter Fontina Tips, FAQ & printable recipe

Tips for success

For the best béchamel, warm the milk before adding it to the roux—this prevents lumps and speeds up thickening. If you do get lumps, whisk vigorously or strain the sauce.

To enhance the nutty flavor of the brown butter, let it cook until the milk solids turn deep golden, but watch it closely to avoid burning. Use a heavy-bottomed saucepan for even heat distribution.

When layering the lasagna, press the noodles gently into the sauce to ensure they are fully coated. If the noodles stick up, they won’t soften properly.

The cast iron skillet retains heat beautifully, so the lasagna stays warm at the table for a long time. For extra crispness, place the skillet under the broiler for the last minute or two, but watch it carefully to prevent burning.

Variations

• Add Mushrooms: Sauté 8 oz sliced cremini mushrooms in butter until golden and add them to the squash layer. The earthy mushrooms complement the sage and brown butter beautifully.
• Use Spinach: Add a layer of baby spinach leaves (about 2 cups) between the lasagna layers. The spinach wilts as it bakes, adding color and nutrients.
• Make It Gluten-Free: Use gluten-free lasagna noodles and substitute the all-purpose flour with a 1-to-1 gluten-free flour blend. Ensure the blend is suitable for béchamel.
• Add Sausage: Brown 1/2 lb Italian sausage and crumble it into the squash mixture. This adds a savory, meaty element that pairs well with the sage and fontina.

Storage and make-ahead

Fridge

Store leftover lasagna in an airtight container in the refrigerator for up to 4 days. Reheat in a 350°F oven until hot, about 15 minutes.

Freezer

Freeze the fully baked and cooled lasagna in a freezer-safe container for up to 3 months. Thaw overnight in the refrigerator before reheating.

Reheat

Reheat individual slices in the microwave for 1-2 minutes, or in a skillet over medium heat until hot and bubbling.

Store leftover lasagna in an airtight container in the refrigerator for up to 4 days. To reheat, place a portion in the microwave or in a small skillet over medium heat until hot.

The lasagna can also be reheated in a 350°F (175°C) oven for about 15 minutes. Leftovers taste even better the next day as the flavors meld.

The lasagna can be assembled up to a day in advance. Prepare the béchamel and roast the squash, then layer everything in the skillet, cover, and refrigerate.

When ready to bake, add 10 to 15 minutes to the baking time, or let it sit at room temperature for 30 minutes before baking. The crispy sage garnish is best added just before serving.

Serving ideas

Serve the lasagna hot from the skillet, scooping out generous portions that show the cheese stretch. Pair it with a simple green salad dressed with lemon vinaigrette to cut through the richness. A glass of dry white wine, such as Sauvignon Blanc or Pinot Grigio, complements the nutty béchamel and squash.

For a heartier meal, add a side of garlic bread or roasted vegetables. The lasagna is substantial enough to be a main course, but it also works as a side dish for roasted chicken or pork. Garnish with extra crispy sage leaves and a dusting of Parmesan at the table for a beautiful presentation.

Frequently asked questions

Recipe card

One-Skillet Butternut Sage Lasagna with Brown Butter Fontina

Prep 30 minCook 45 minRest 10 minTotal 1 h 25 minServes 6

Ingredients

• 1 medium butternut squash, peeled, seeded, and thinly sliced
• 1/2 cup fresh sage leaves, divided
• 8 oz fontina cheese, grated
• 1/2 cup grated Parmesan cheese, divided
• 12 sheets no-boil lasagna noodles
• 4 tbsp unsalted butter
• 3 tbsp all-purpose flour
• 2 cups whole milk
• 1 tsp kosher salt
• 1/2 tsp black pepper
• 1/4 tsp ground nutmeg

Instructions

1. Heat the oven to 400°F (200°C). Peel the butternut squash, cut it in half lengthwise, scoop out the seeds, and slice it thinly, about 1/8-inch thick. Set the slices aside. Pick the sage leaves from the stems and set aside. Grate the fontina cheese on the large holes of a box grater and grate the Parmesan finely. Keep them separate.
2. Spread the squash slices on a baking sheet in a single layer. Roast for 15 minutes, until just tender and lightly browned at the edges. Remove from the oven and set aside. Leave the oven on for baking the lasagna.
3. In a medium saucepan over medium heat, melt the butter. Add the sage leaves and cook, stirring, until the butter foams and turns golden brown and the sage is fragrant, about 3 minutes. Sprinkle in the flour and whisk constantly for 1 minute. Slowly pour in the milk, whisking to prevent lumps. Cook, whisking, until the sauce thickens and coats the back of a spoon, about 5 minutes. Stir in salt, pepper, and nutmeg. Remove from heat.
4. Spread a thin layer of béchamel on the bottom of a 10-inch cast iron skillet. Arrange 4 lasagna noodles over the sauce, breaking them to fit if needed. Layer with half of the roasted squash, a third of the remaining béchamel, and a third of the fontina. Repeat with another layer of noodles, the remaining squash, half of the remaining béchamel, and half of the remaining fontina. Top with the last noodles, the rest of the béchamel, and the rest of the fontina.
5. Place the skillet in the oven and bake for 25 to 30 minutes, until the top is golden and the cheese is bubbling and blistered in spots. Let the lasagna rest for 10 minutes before serving.
6. While the lasagna rests, heat a small skillet with a little oil over medium heat. Add the remaining sage leaves and fry until crisp, about 30 seconds per side. Drain on paper towels. Sprinkle the lasagna with the crispy sage leaves and the remaining grated Parmesan. Cut into wedges and serve hot, pulling up a portion to show the cheese stretch.

Contains: gluten, milk

Estimated nutrition per serving

Calories

420

Protein

18 g

Carbohydrates

35 g

Fat

24 g

Automatic estimate from the ingredient list, not laboratory-verified.