– 2 tablespoons unsalted butter
– 1 tablespoon olive oil
– 1 medium yellow onion, finely chopped
– 1 fresh thyme sprig
– 1 fresh oregano sprig
– 1/2 teaspoon salt
– 1/4 teaspoon freshly ground black pepper
– 1 medium carrot, finely chopped
– 1 celery stick, finely chopped
– 1 lb. ground beef chuck
– 2 garlic cloves, crushed
– 1 cup chopped or crushed tomatoes
– 1/2 cup tomato puree
– 1/2 cup water
– 1 teaspoon salt
– 8 ounces (10 noodles) wavy lasagna noodles, broken into 2-inch pieces
– Water, as needed
– 8 ounces mozzarella cheese, diced