Take frozen beef (400 grams) and let it cook until slightly browned, no need to add oil as the meat will render its own fat.
Chop one celery stalk, one onion, one carrot, and four garlic cloves finely. Tumis these ingredients until they are soft and lightly golden brown on the edges.
Add tomato puree (one can) and blend two fresh tomatoes with a little water. Pour this mixture into the pan.
Bring to a simmer, add half a tablespoon of oregano for flavor, and one teaspoon of chili flakes for some heat if desired. Add salt and black pepper to taste.
Add chicken bouillon cubes or any leftover beef stock to enhance the broth. Cover and let it cook for about 15 minutes until well-seasoned.
Follow the cooking time instructions on the spaghetti packaging (8-10 minutes). Once cooked, drain the pasta and place it in a serving dish.
Pour the prepared bolognese sauce over the spaghetti and sprinkle with grated parmesan cheese. Serve immediately and enjoy your meal.