INSTRUCTIONS
1. Position a rack in the lower third of an oven and preheat to 400°F.
2. In a large nonstick fry pan over medium-high heat, warm the olive oil. Add the onion and cook, stirring occasionally, until soft and translucent, about 8 minutes. Add the garlic, salt and pepper and cook for 30 seconds. Transfer to a bowl.
3. In the fry pan over medium-high heat, cook the sausage, breaking it into small pieces, until browned and cooked through, about 8 minutes. Drain the sausage on paper towels, then add to the onion mixture.
4. In the fry pan over medium heat, melt the butter. Add the flour and cook, stirring constantly, for 1 minute. Slowly stir in the milk, increase the heat to medium-high and cook until thickened, 8 to 10 minutes. Transfer to a separate bowl. Stir in ¾ cup of the cheese, the ¼ cup parsley, the sage, salt and pepper.
5. To assemble the lasagna, spread 1/3 cup sauce on the bottom of the fry pan and top with a single layer of 3 noodles. Top with 1/3 cup sauce, 1/3 cup sausage and a layer of squash slices. Repeat the layering of sauce, sausage and squash 5 more times, replacing the squash layer with a layer of noodles after every 2 layers of squash. Top with the remaining sauce and the ¼ cup cheese.
6. Transfer the pan to the oven and bake until the lasagna is browned and bubbly, about 45 minutes. Sprinkle with the 1 Tbs. parsley. Let the lasagna stand for 15 minutes before slicing.
