Everyone knows that despite being freshly cut, the pale and soggy fries are In-N-Out’s weakest point, but if you smother them in cheese, sweet caramelized onions, and In-N-Out spread, they’re magical. So replacing the sad fries with crispy frozen fries really is an improvement over the originals here. Spread is just a basic sweet and tangy burger sauce with mayo, ketchup, relish, a little sugar, and a little vinegar. The onions are really the stars here – soft, sweet, and jammy. Be sure to serve immediately as soon as the fries are cooked – the residual heat of the fries and the onions is what melts the cheese.
Prep Time::15 mins
Cook Time:: 1 hr
Total Time:: 1 hr 15 mins
Servings::4
Ingredients
Spread:
½ cup mayonnaise
3 tablespoons ketchup
2 tablespoons sweet pickle relish
1 ½ teaspoons white sugar
1 teaspoon distilled white vinegar
Grilled Onions:
2 tablespoons unsalted butter
1 tablespoon canola oil
4 ½ cups chopped yellow onion
1 teaspoon kosher salt
4 tablespoons water, divided
Fries:
1 (28 ounce) package frozen shoestring potato fries
4 slices American cheese
Directions
Prepare the Spread: Whisk together mayonnaise, ketchup, relish, sugar, and vinegar in a small bowl until well combined. Cover and set aside until serving.
Prepare the Grilled Onions: Heat butter and oil in a large skillet over medium. Add onions and salt; cook, stirring occasionally, until softened and golden brown, about 20 minutes. When skillet starts to become dry, add 1 tablespoon of water. Continue cooking, stirring often, adding more water, 1 tablespoon at a time, as needed, until onions are very soft, deeply browned, and jammy, 10 to 15 more minutes (you may not need to use all the water). Cover and set aside to keep warm.
Prepare fries according to package instructions.
Divide fries evenly among 4 plates; immediately top with 1 slice cheese, 3 tablespoons grilled onions, and 3 tablespoons spread.
Cook’s Note
To prep ahead, you can make the spread and store in an airtight container in the fridge for up to 5 days. You can also cook the onions and store in an airtight container in the fridge for up to 5 days (reheat before adding them to the fries).