Page 207 - My Cookbook

INGREDIENTS
For the sauce:
1 tablespoon extra-virgin olive oil
1 pound sweet Italian sausage, casings removed
1 medium onion, chopped
3/4 teaspoon kosher salt
1/4 teaspoon freshly ground black pepper
4 garlic cloves, minced
1/2 teaspoon red-pepper flakes, plus more to taste
2 tablespoons tomato paste
Two 28-ounce cans whole tomatoes
2 teaspoons dried oregano
For the filling:
Two 15-ounce containers part-skim ricotta cheese
Lasagna with Sausage, Spinach, and Three Cheeses

Pasta
Prep 40 minutes ∙ Cook 1 hour 45 minutes ∙ Makes 8 to 10 servings ∙ Source Epicurious.com
DIRECTIONS
Position the rack in the upper third of the oven and preheat to 375°F.
Make the lasagna noodles according to directions.
Make the sauce:
In a large pot over medium-high heat, heat the oil. Add the sausage, onion and 3/4 teaspoon salt and 1/4 teaspoon pepper; cook, breaking up sausage with a wooden spoon, until browned and cooked through, 8 to 10 minutes. Reduce heat to medium and add garlic, red- pepper flakes, and tomato paste; cook, stirring often, until fragrant, 1 to 2 minutes more. Add tomatoes (along with their juice) and oregano; bring to a simmer, and cook, breaking up the tomatoes with a wooden spoon until in small pieces, about 5 minutes. Taste and adjust seasoning, adding more red-pepper flakes if desired.
Make the filling:
In the bowl of a food processor, combine all of the filling ingredients and process until mostly smooth.
Assemble the lasagna: