Quick Recipe Version (TL;DR)
Quick Ingredients
- 1 large butternut squash (about 2.5 lb), peeled and cubed
- 12 no-boil lasagna sheets
- 10 oz baby spinach (or 10 oz frozen, thawed and squeezed)
- 16 oz whole-milk ricotta + 1 large egg
- 8 oz Gruyère, shredded (about 2 cups)
- 3/4 cup finely grated Parmesan, divided
- 4 cups whole milk
- 4 tbsp unsalted butter + 2 tbsp for crumbs
- 1/4 cup all-purpose flour
- 2 garlic cloves, minced (divided)
- 3 tbsp fresh sage, finely chopped (divided)
- 3/4 cup panko + 3/4 cup finely chopped walnuts
- Olive oil, kosher salt, black pepper, pinch nutmeg
- 1/4 cup hot water (for the pan edges)
Do This
- 1. Heat oven to 400°F. Toss squash with 2 tbsp oil, 1/2 tsp salt, and pepper; roast 30–35 minutes until tender and caramelized. Reduce oven to 375°F.
- 2. Toast crumbs: in a skillet, melt 2 tbsp butter with 1 tbsp oil; add panko, walnuts, 1 tbsp sage, and a pinch of salt; stir 4–5 minutes until golden. Set aside.
- 3. Wilt spinach in 1 tsp oil with half the garlic; season with a pinch of salt and pepper. Squeeze out excess moisture.
- 4. Make béchamel: melt 4 tbsp butter, whisk in 1/4 cup flour 1 minute; gradually whisk in 4 cups warm milk. Add remaining garlic, 1 tbsp sage, 1 tsp salt, 1/4 tsp pepper, and a pinch nutmeg; simmer 6–8 minutes to thicken.
- 5. Stir ricotta with egg, 1/4 cup Parmesan, 1/4 tsp salt, 1/8 tsp pepper, and a pinch nutmeg.
- 6. Assemble in a greased 9×13: 1 cup béchamel, noodles, 1 cup squash, 1/3 ricotta, 1/3 spinach, 1/3 cup Gruyère, 1/2 cup béchamel. Repeat for 3 layers. Top with noodles, 1.5 cups béchamel, 1 cup Gruyère, 1/2 cup Parmesan. Pour 1/4 cup hot water around edges; cover with foil.
- 7. Bake 25 minutes covered; uncover, scatter walnut crumbs, and bake 10–12 minutes more (broil 1–2 minutes if needed). Rest 15 minutes before slicing.
Why You’ll Love This Recipe
- Comforting layers of sweet roasted butternut, creamy ricotta, and melty Gruyère balanced by fragrant sage.
- Festive toasted walnut breadcrumbs add a crunchy, nutty finish that keeps every bite interesting.
- No-boil noodles and a straightforward sage béchamel make this feel special without being fussy.
- Perfect make-ahead vegetarian main for gatherings and holiday dinners.
Grocery List
- Produce: 1 large butternut squash, 10 oz baby spinach, 2 garlic cloves, 1 small bunch fresh sage
- Dairy: Whole milk (4 cups), unsalted butter, whole-milk ricotta (16 oz), Gruyère (8 oz), Parmesan, 1 large egg
- Pantry: No-boil lasagna sheets (12), panko breadcrumbs, walnuts, all-purpose flour, olive oil, kosher salt, black pepper, ground nutmeg
Full Ingredients
Roasted Butternut Layer
- 1 large butternut squash (about 2.5 lb/1.1 kg), peeled, seeded, cut into 1-inch cubes
- 2 tbsp extra-virgin olive oil
- 1/2 tsp kosher salt
- 1/4 tsp freshly ground black pepper
- Up to 2 tbsp milk, optional (to loosen mash if needed)
Spinach Layer
- 10 oz fresh baby spinach (or 10 oz frozen chopped spinach, thawed and squeezed dry)
- 1 tsp olive oil
- 1 small garlic clove, minced
- Pinch kosher salt and black pepper
Sage Béchamel
- 4 tbsp unsalted butter
- 1/4 cup all-purpose flour
- 4 cups whole milk, warmed
- 1 garlic clove, finely minced or grated
- 1 tbsp fresh sage, finely chopped
- 1 tsp kosher salt
- 1/4 tsp freshly ground black pepper
- 1/8 tsp ground nutmeg
Ricotta & Cheeses
- 16 oz whole-milk ricotta
- 1 large egg
- 3/4 cup finely grated Parmesan, divided (1/4 cup for ricotta; 1/2 cup for topping)
- 8 oz Gruyère, shredded (about 2 cups; 1 cup for top, 1 cup for inside layers)
- 1/4 tsp kosher salt
- 1/8 tsp black pepper
- Pinch ground nutmeg
Toasted Walnut Breadcrumb Topping
- 3/4 cup panko breadcrumbs
- 3/4 cup walnuts, finely chopped
- 2 tbsp unsalted butter
- 1 tbsp olive oil
- 1 tbsp fresh sage, finely chopped
- 1/8 tsp kosher salt
Assembly
- 12 no-boil lasagna sheets
- 1 tsp olive oil or butter for greasing the pan
- 1/4 cup hot water (to pour around the pan edges before baking)
Step-by-Step Instructions
Step 1: Roast the butternut squash
Heat the oven to 400°F (200°C). Toss the cubed squash with 2 tbsp olive oil, 1/2 tsp kosher salt, and 1/4 tsp pepper on a large rimmed baking sheet. Spread in a single layer and roast for 30–35 minutes, stirring once, until tender with caramelized edges. Lightly mash with a fork; if it seems very dry, stir in up to 2 tbsp milk to make a spreadable mash. Reduce the oven to 375°F (190°C).
Step 2: Toast the walnut breadcrumbs
In a medium skillet over medium heat, melt 2 tbsp butter with 1 tbsp olive oil. Add panko, walnuts, 1 tbsp chopped sage, and 1/8 tsp salt. Cook, stirring constantly, until golden and fragrant, 4–5 minutes. Transfer to a bowl to stop the cooking and keep crisp.
Step 3: Wilt the spinach
In the same skillet, heat 1 tsp olive oil over medium heat. Add the minced garlic and cook 30 seconds. Pile in the spinach and toss until just wilted, 1–2 minutes (or simply warm and dry out thawed frozen spinach). Season with a pinch of salt and pepper. Transfer to a colander and press out excess moisture.
Step 4: Make the sage béchamel
In a saucepan over medium heat, melt 4 tbsp butter. Whisk in 1/4 cup flour and cook, whisking, for 1 minute. Gradually add the warm milk, whisking smooth after each addition. Stir in the remaining garlic, 1 tbsp chopped sage, 1 tsp salt, 1/4 tsp pepper, and a pinch of nutmeg. Simmer, whisking occasionally, until thick enough to coat a spoon, 6–8 minutes. Remove from heat.
Step 5: Mix the ricotta filling
In a bowl, combine ricotta, egg, 1/4 cup Parmesan, 1/4 tsp salt, 1/8 tsp pepper, and a pinch of nutmeg. Stir until creamy and smooth.
Step 6: Assemble the lasagna
Grease a 9×13-inch (3-quart) baking dish. Spread 1 cup béchamel in the bottom. Add a layer of 4 no-boil noodles (trim if needed). Layer as follows and repeat for a total of 3 inner layers: 1 cup mashed squash, about 2/3 cup ricotta mixture (dolloped and spread), one-third of the spinach, 1/3 cup shredded Gruyère, then drizzle with 1/2 cup béchamel. Finish with a final layer of noodles, top with the remaining 1.5 cups béchamel, 1 cup Gruyère, and 1/2 cup Parmesan. Pour 1/4 cup hot water around the inside edges of the pan. Cover tightly with foil.
Step 7: Bake and add the crunchy topping
Bake at 375°F (190°C) for 25 minutes. Uncover, scatter the walnut breadcrumbs evenly over the top, and bake another 10–12 minutes until bubbling and golden. If needed, broil for 1–2 minutes to deepen the color—watch closely to prevent burning.
Step 8: Rest, slice, and serve
Let the lasagna rest for 15 minutes so the layers set. Slice into 8 squares. Garnish with a few small sage leaves if you like, and serve warm.
Pro Tips
- Coat the pan edges with béchamel and add a splash of hot water before baking to ensure no-boil noodles hydrate fully.
- Warm the milk before making béchamel; it blends faster and prevents lumps.
- Press moisture from the spinach so the lasagna layers don’t slide or water out.
- Let it rest: 15 minutes of cooling yields cleaner slices and better texture.
- For extra sage aroma, sizzle whole sage leaves in a teaspoon of butter and tuck them on top as a garnish.
Variations
- Mushroom addition: Sauté 8 oz sliced cremini with thyme and layer with the spinach for an earthier profile.
- Cheese swap: Sub Comté or Fontina for Gruyère; both melt beautifully and keep the nutty, alpine vibe.
- Gluten-free: Use gluten-free no-boil lasagna sheets and substitute a 1:1 gluten-free flour blend for the béchamel and gluten-free panko for the topping.
Storage & Make-Ahead
Assemble up to 24 hours in advance, cover, and refrigerate. Bake straight from the fridge at 350°F for 45–55 minutes (add crumbs in the last 10 minutes). Leftovers keep 4 days refrigerated; reheat covered at 350°F for 20–25 minutes. To freeze: wrap the unbaked casserole tightly in plastic, then foil, up to 2 months. Bake from frozen at 350°F for 60–75 minutes covered, then uncover and add crumbs for the last 10–15 minutes. Baked leftovers can also be frozen in portions; thaw overnight before reheating.
Nutrition (per serving)
Approximate: 710 calories; 38 g fat; 57 g carbohydrates; 28 g protein; 5 g fiber; 1,020 mg sodium. Values will vary based on brands and exact measurements.
