Blow-Your-Mind Butternut Squash, Caramelized Onion, and Spinach Lasagna

All the pretty layers.
All the pretty layers.

This is the only veggie lasagna recipe you will ever need. Yes I know; that is a bold statement, but I am prepared to back it up. You know me, I am constantly trying new recipes, always on the hunt for a real gem. While most of the recipes I try are perfectly good, it is rare that I find an actual gem – one that I would make again and again… and again. Of course all the recipes I share here have passed that test, but even among these recipes, I have to say, this is one of my absolute favorites. It’s so yummy and pretty I can make it for guests, or whip it up on a Sunday night for the hubby and me to have for lunches during the week. I have made this lasagna countless times, and let me promise you: This. Recipe. NEVER. Fails. The tastes are perfectly balanced; the cream sauce is BRILLIANT; and leftovers hold up well. Get ready, friends, for this blow-your-mind Butternut Squash, Caramelized Onion, and Spinach Lasagna.

Butternut Squash, Caramelized Onion, and Spinach Lasagna

adapted practically not at all from this Cooking Light Recipe

Cooking and prep time: about 2 hours (active 1hr 15 mins)   Serves 8
360 calories; 12g fat; 17g protein; 50g carbs

no-boil lasagna noodlesIngredients

  • 6 cups (1/2-inch) cubed peeled butternut squash
  • 2 T olive oil
  • 2 T chopped fresh sage, or 2 tsp dry
  • 12 garlic cloves, unpeeled (about 1 head)
  • 1 tsp kosher salt
  • 1/2 tsp black pepper
  • Cooking spray
  • 1 large onion, vertically sliced
  • 2 T water
  • 18 oz fresh spinach
  • 5 cups 1% low-fat milk
  • 1 bay leaf
  • 1 thyme sprig
  • 5 tablespoons flour
  • 1 1/2 cups (6 oz) shredded fontina cheese, or any white cheese that you like. I’ve used aged provolone, or mixed in some mozzarella – whatever you have on hand will be fine.
  • 3/8 tsp ground red pepper
  • 1/4 tsp grated nutmeg
  • 9 no-boil lasagna noodles, like the ones on right. (Only have regular boil noodles? Never fear; click here. But seriously, the no-boil ones are awesome.)


There are several steps to this lasagna, but the key is getting several things going at once. When the squash goes into the oven, start the onions caramelizing. While the onions are caramelizing, start the cream sauce bubbling, and so on.

Make the squash layer

Preheat oven to 425°.

Combine squash, 1 T oil, sage, garlic,* 1/2 tsp salt, and black pepper in a large bowl; toss to coat. Transfer squash mixture to a baking sheet or pyrex coated with cooking spray (I needed to use two).

*note: it is very important to leave the SKIN ON the garlic cloves. If not, the garlic will dry out, and you want it nice and soft and moist.

Bake at 425° for 30 minutes or until squash is tender. Cool slightly; peel garlic. Be warned – this is a messy, sticky job and your hands will smell like roasted garlic for days. Place squash and garlic in a bowl; partially mush with a fork. You can stop right now if you like and just eat this garlicky-squash mash – it is divine.

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While the squash is roasting, make the onion and spinach layer

Heat remaining 1 T oil in a large Dutch oven or wok over medium-high heat. Add onion, and sauté for 4 minutes. Reduce heat to medium-low; continue cooking for 20 minutes or until golden brown, stirring frequently. This will get them nice and caramelized. Move onions to a bowl.

In the same pot/pan, add 2 T water and ALL the spinach; increase heat to high. It will fill up the pan, but it cooks down quickly, don’t worry. Cover and cook 2 minutes or until spinach wilts. Drain in a colander; cool and press out any excess liquid. Add spinach to onions.

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While the onions are caramelizing, make the cream sauce

Make the cream sauceHeat 4 1/2 cups milk, bay leaf, and thyme in a medium saucepan over medium-high heat. Bring to a boil,  but for heaven’s sake keep a close eye on your pot, or you will end up with a milky, frothy mess all over the stove. Not that I speak from experience or anything… I know that a watched pot never boils but I swear I turned my back for 2 seconds and the whole thing bubbled over.

Once it boils, remove from heat and let stand for 10 minutes. Discard the spices and return pan to medium heat.

Combine remaining 1/2 cup milk and flour in a small bowl. Add to pan, whisking until combined. Bring to a boil (WATCH YOUR POT!); reduce heat, and simmer for 5 minutes or until thickened, stirring constantly. Remove from heat; stir in remaining 1/2 tsp salt, 1 1/4 cups cheese, red pepper, and nutmeg.


Finally, assemble!

Spread 1/2 cup milk mixture in bottom of a 13 x 9-inch glass or ceramic baking dish coated with cooking spray. Place 3 noodles over milk mixture; top with half of squash mixture, half of spinach mixture, and 3/4 cup milk mixture. Repeat layers, ending with noodles on the top. Spread remaining milk mixture over noodles.

Bake at 425° for 30 minutes, and remove from oven. Sprinkle with remaining 1/4 cup cheese.

Preheat broiler, and broil lasagna 2 minutes or until cheese is melted and lightly browned. Let the dish stand 10 minutes before serving… if you can  wait that long!

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