Heat campfire or grill to medium, set up for direct heat.
Heat salsa in a 12-inch cast-iron skillet until warm, 4 to 5 minutes. Add chips and cook, gently tossing, until just softened, 3 to 4 minutes. Remove from grill and cover to keep warm.
Heat oil in a 10-inch cast-iron skillet until warm. Crack eggs into the skillet and cook, covered with a piece of aluminum foil, to desired doneness, 4 to 6 minutes for slightly runny sunny-side up. Season with pepper.
Top the chips and salsa mixture with eggs, feta, avocado, radishes, and cilantro. Serve immediately.