Preheat your oven to 400°F.
This helps to achieve the perfect top layer on your lasagna.
Cook the onion in olive oil over medium-low heat until translucent.
This usually takes about 5 minutes.
Add garlic and turkey sausage to the onion.
Cook until no longer pink, breaking up the sausage with a spoon.
Mix in tomato paste and crushed tomatoes.
Let the ingredients simmer together for about 20 minutes.
Prepare the cheese mix by combining ricotta, one egg, chopped parsley, and 1/2 of the Parmesan cheese in a bowl.
Soak noodles in hot water for about 20-30 minutes.
This step softens them without pre-boiling.
Layer noodles, cheese mix, sauce, and mozzarella in a baking dish.
Repeat layers and top with remaining Parmesan.
Bake for 45 minutes, or until golden and bubbly.
The cheese should be fully melted.