Turn slow cooker setting to 4.

Sautee celery, onions and bellpeppers in margarine, stovetop. Pour mixture into slow cooker. Add garlic and diced tomatoes. Stir and cover. Allow to cook undisturbed for 5-10 minutes.

On the stovetop, add boullion cubes and 5 cups of water. Heat until boullion cubes dissolve. Reduce heat and simmer for 2 minutes.

On the stovetop, brown the fajita beef in olive oil. Add beef and drippings to the slow cooker. Stir.

Add 5 cups of broth to the slow cooker. Stir and allow to cook for 30 mins.

Add red potatoes and cook for 30 minutes.

Add carrots and cook for 30 minutes.

Add spaghetti and cook for 15 minutes.

Add corn and peas and cook an additional 15 minutes.

Potatoes and carrot should be tender at this point. If not, cook until tender.