In a medium-sized pan, heat oil and sauté onions until they become translucent, typically taking about 2-3 minutes.
Introduce diced tomatoes, green chilies, cumin, and season with salt and pepper. Stir occasionally and let the mixture simmer for a few minutes. Once done, set aside to retain warmth.
In a separate non-stick skillet, spray the tortillas lightly with olive oil on both sides. Heat on medium-high until they turn crispy and form air bubbles, usually about 1-2 minutes on each side. Once crisped, set them aside.
In the same skillet, lower the heat to medium-low. Spray a bit more oil and crack in the eggs. Season with salt and pepper. For sunny-side-up eggs, cover and let them cook until the egg whites set. For other preferences, adjust the cooking time.
Serving suggestion: On each plate, lay down two tortillas. Top them with half of the tomato mixture, two fried eggs, a sprinkle of lettuce, cheese, and finish with a sprinkle of cilantro.