Add the tomatoes and water to a small pot over medium heat. Simmer the tomatoes until soft and stir in the garlic and chicken broth powder.
While tomatoes are cooking, heat grill to medium. Grill and char the chiles on both sides. Once blackened put in a plastic bag for 10 minutes to sweat out any moisture.
While the chiles sweat, add the 1/4 cup of oil to a frying pan, over low heat, and stir in the flour to make a roux mixture. Cook the flour until browned, then add the tomato sauce. Simmer for 5 minutes and then add the oregano. Continue simmering, stirring occasionally.
Remove from the bag, remove charred skin, slit them down the middle and remove the seeds. Stuff the peppers with the queso fresco and use toothpicks to hold them together.
Separate the egg yolks from the whites. Add the egg whites to a large bowl. Reserve the egg yolks. Beat the egg whites with an electric beater until the whites fluff up. Add in the flour and the egg yolks and mix until completely incorporated.
Add the oil to a frying pan over medium heat. Dip the stuffed peppers into the batter and fry until golden brown on both sides. Remove from the oil to a serving platter.
Pour the tomato sauce over the cooked chile rellenos on the serving platter and serve. If desired, serve with rice and beans.