Heat oil in a 12-inch non-stick skillet over medium heat. Add onions and cook until translucent, about 5 minutes. Remove onions from skillet and set aside. Add Knorr(R) Fiesta Sides(TM) - Mexican Rice to skillet and cook according to package directions.
Whisk eggs and cream together in a large bowl until well combined and frothy.
Add onions, ham, green chiles and tomatoes to rice in pan; stir well to combine. Slowly pour in egg mixture; stir gently. Reduce heat to low and cover.
Push mixture from the sides to the center with a spatula, allowing uncooked eggs from top of egg skillet to seep down to the bottom, then re-cover. Do this several times, every few minutes, until eggs are just about set.
Stir in 1 cup shredded Cheddar cheese; add remaining cheese to top of egg skillet. Cover and allow cheese to melt. Season with salt and pepper to taste. Serve immediately.