Preparation

• Bring a small pot of water to a slow simmer over low heat and keep it warm.

• Heat the oil in a large nonstick pan over medium-low heat. Add the onions, season with salt and pepper, and cook 20 to 30 minutes, until the onions are very soft, taking care not to let them get caramelized and adding a little hot water if the pan starts to get dry.

• First, raise the heat to medium. This is where it gets a little tricky: Using the large holes of a box grater, grate the potatoes right into the pan with the onion (If that seems a little daunting, quickly grate them into a bowl and add them to the pan all at once.). Using two wooden spoons, work the potatoes and onions together until they are fully incorporated into a very sticky and wet paste; this will take about 5 minutes. Work that paste! We want to make it as homogenous as possible.

• Add the cheeses to the potato mixture. Using two wooden spoons, work the mixture—grabbing it, lifting it up, stretching it and repeating—until all the cheese is melted and incorporated and you have a uniform paste; this will take about 5 minutes.

• Smooth the mixture into an even layer to cover the pan’s bottom and cook until lightly browned on the bottom, 5 to 10 minutes (Use a spatula to lift and check on the color of the bottom crust.). Place a large round plate upside down on top of the pan. Turn off the heat, then very rapidly invert the pan and the plate together so the frico ends up on the plate. Set the pan back on the stove, slide the frico back into the pan, and turn heat to a medium-low. Continue to cook until a light brown crust brown crust forms on the bottom, 5 to 10 minutes.

• I suggest serving this classic on a large wooden tray or even a cutting board.

Luca’s Tips:
Three simple but very important steps will give you a perfect frico: 1) Cook down the onions very slowly; 2) Grate the potatoes—don’t cut, chop or shave them; and 3) Most important, you absolutely need a nonstick pan to get that all-important crust. Don’t even waste your time if your nonstick is old and scratched—it will be impossible to flip your frico. It just won’t work!