Tortilla Española is kind of like a potato omelet except it's more about the potatoes than the eggs, and kind of like a fritata except it's flipped in the pan instead of finished off in the oven. Doesn't matter what you call it, it still tastes great for breakfast, lunch or dinner.
Start off by sauteing thinly sliced potatoes in some olive oil, just until they're cooked and softened, then set them aside. Then saute half an onion and same garlic until they're softened and translucent, but not browned. Combine the potatoes, onion and garlic with some beaten eggs. Make sure to mix up the potato slices so that any that are stuck together get egg in between.
Turn the heat up on the pan to med/high, pour the egg/potato mixture in and lower the heat to medium/low and cook until the edges firm up. Here comes the fun part-the flip. Place a plate on top of the pan and flip the half-cooked tortilla onto the plate, put the pan back on the burner and slide the tortilla back into the pan. Cook until it's done and serve in wedges.