Put the peppers over the flame. Grilled turning frequently, until the skin is burned and blistered evenly. Remove from heat, place in a plastic bag and let them sweat for a few minutes.
This allows you to easily peel
Then put the meat in a pan over medium-high heat. Stir so that detach and let it cook evenly. When meat is cooked, add the onion, garlic and tomato. Cook for a few minutes. Season with salt and pepper to taste.
Also take the peppers from the bag and peel. I suggest you to wear gloves. If you want you can rinse thoroughly with cold running water to remove any burnt stub.
Make a vertical cut on one side of the peppers, making sure you do not break, remove the seeds and veins. Since they are clean, half filled with meat and half with cheese.
Beat the egg whites in a glass or metal until thick and fluffy. Add the yolks in surrounding form until well incorporated.
Deep in oil in a large skillet over medium-high heat. Spend chiles rellenos by the flour and then dip them in the egg mixture until completely covered.
Place carefully in the hot oil and fry both sides until the egg is browned. Drain the excess oil on paper towels and serve in a large bowl.
Extra: serve with Salsa Roja (Red Sauce),Sour Cream, Rice and Beans.