In a large skillet, heat olive oil. Add onion and garlic. Cook over medium heat until onions become soft. Add celery and carrot, cook until they soften. Add ground beef and pork. Cook, stirring frequently to break apart large lumps and cook until meat is no longer pink. Add the tomatoes, parsley and salt and pepper to taste. Turn sauce to low and simmer 20-30 minutes.
Bolognese is typically served over tagliatelle pasta (large, flat noodles), but you may use your favorite pasta.