Prep your vegetables. Dice the bell pepper and onion, slice the mushrooms, halve the cherry tomatoes, and roughly chop the spinach. Keep portions small so they cook quickly.

Beat the eggs. Crack 3 eggs into a bowl. Add 1 to 2 teaspoons of milk or water, a pinch of salt and pepper, and whisk just until the yolks and whites are combined. Don’t overbeat.

Warm the pan. Place a nonstick skillet over medium heat. Add 1 teaspoon of olive oil or a small pat of butter.

Sauté the hearty veggies first. Add onion and bell pepper. Cook 2 to 3 minutes, stirring occasionally, until softened. If using mushrooms, add them now and cook until they release their moisture and start to brown, about 2 more minutes.

Add the quick-cooking veggies. Toss in spinach and tomatoes. Cook 30 to 60 seconds, just until the greens wilt and the tomatoes warm. Season lightly with salt and pepper. Transfer veggies to a plate.

Reset the pan. Wipe the skillet quickly with a paper towel if very wet. Add a little more butter or oil and return to medium or medium-low heat.

Add the eggs. Pour in the beaten eggs. Let them sit 10 to 15 seconds, then gently pull the edges toward the center with a silicone spatula, allowing uncooked egg to flow to the edges. Do this around the pan until most of the egg is set but still slightly glossy on top.

Add fillings. Scatter the cooked vegetables over one half. Sprinkle with cheese and any fresh herbs or red pepper flakes.

Fold and finish. Use the spatula to fold the bare side over the fillings. Reduce heat to low and cook 30 to 60 seconds more, just to melt the cheese and finish setting the eggs.

Serve. Slide the omelet onto a warm plate. Add extra herbs, a crack of pepper, and serve with toast, avocado, or a simple salad.