1. heat oil and fry onion and pepper over moderate heat for 3 min, stirring frequently. stir in rice and cook for 1 min. stir in stock and bring to boil.
2. cover pan and simmer for 40 min
3. add tomatoes and avocado, stirring in carefully to avoid breakage. cover and simmer for 5 min.
4. beat eggs with yogurt and season with salt and pepper. pour over rice and fork it over and over. cook until eggs are just set. garnish. serve at once