1 tablespoon olive oil
1 large yellow onion, diced
3 garlic cloves, minced
1/4 cup tomato paste
1 pound ground beef
3/4 teaspoon fine salt
3/4 teaspoon ground black pepper
1/2 teaspoon red pepper flakes
1/2 teaspoon dried oregano
1/2 teaspoon dried rosemary
1 (28-ounce) can whole tomatoes
6 cups chicken stock
8 ounces lasagna noodles, roughly broken
8 ounces whole milk ricotta
1/4 cup grated Parmigiano-Reggiano
1/2 cup shredded low-moisture mozzarella
1/4 cup fresh basil leaves, to serve