How to Make It
Combine the onion and vinegar in a non-reactive bowl and set aside, at least 15 minutes.
Heat oil in a large skillet over medium. Add bell pepper and garlic and cook, stirring often, until pepper is slightly tender, 3 to 4 minutes. Add tomatoes and their juices, gochujang, 1 teaspoon cumin, ¾ teaspoon salt and ¼ teaspoon pepper. Bring the mixture to a simmer and cook, breaking up the tomatoes with a wooden spoon, until the sauce is bubbling and thickened, 8 to 10 minutes. Sprinkle feta overtop. Using the back of the spoon, create 4 shallow wells in the sauce and gently crack an egg into each one. Cover skillet and cook until until the whites are set but yolks are still runny, 3 to 4 minutes. Serve with pita.
Drain the onions (reserve vinegar for salad dressings). Top the eggs with parsley, dill, and pickled onions. Serve with warm pita.