Prep the veggies. Finely chop the bell pepper and onion. Roughly chop the spinach so it wilts faster and blends into the filling. If using tomato, seed it so the quesadilla doesn’t get watery.

Beat the eggs. In a bowl, whisk the eggs with a pinch of salt, pepper, and a little garlic powder. If you like it creamier, add a tablespoon of milk or water.

Soften the veggies. Heat a nonstick skillet over medium heat and add a teaspoon of oil or butter. Sauté the onion and pepper for 2–3 minutes until tender and slightly sweet.

Hide the spinach. Add the chopped spinach to the pan. Cook for 30–60 seconds until wilted and dark green. It will shrink a lot, which helps it blend in.

Scramble gently. Pour the beaten eggs over the veggies. Stir slowly, pushing from the edges toward the center. Cook until just set and still glossy—about 1–2 minutes. Remove to a plate.

Build the quesadilla. Wipe out the skillet if needed. Place a tortilla in the pan over medium heat. Sprinkle half the cheese over one side, add the egg-veggie mixture, then sprinkle the rest of the cheese. Fold the tortilla in half.

Crisp and melt. Cook 2–3 minutes per side, pressing lightly with a spatula, until the tortilla is golden and the cheese is melted. Adjust heat so it browns without burning.

Rest and slice. Transfer to a board, let it sit for 1 minute, then slice into wedges. Serve with salsa, a dollop of Greek yogurt, or hot sauce.

Repeat for more. For multiple quesadillas, keep cooked ones warm in a low oven (200°F/95°C) directly on the rack so they stay crisp.