3 tablespoons EVOO

4 ounces pancetta, finely chopped

1 small onion, finely chopped

1 carrot, finely chopped

1 rib celery, finely chopped

1 clove garlic, minced

1 bay leaf

1/2 teaspoon dried thyme

1 pound 85% lean ground beef chuck

1 can (28 oz) crushed tomatoes

salt and pepper

4 tablespoons butter

1/4 cup flour

2 1/2 cups whole milk, warmed

1 1/4 cups grated parmesan

3/4 pound dried lasagna noodles