Easy + Cheesy French Onion Fries

5 from 1 vote

These French onion fries make a delicious, comforting appetizer or side dish, great for fans of French onion soup!

Cook Time1

Total Time1

Course: Appetizers, Side Dish

Cuisine: American, French

Diet: Gluten Free, Vegetarian

Servings: servings

Calories: 953kcal

Get Recipe Ingredients

Melt butter in a small pot or skillet over low heat, then add thinly sliced onions and salt. Caramelize over lowest possible heat for 30-45 minutes until deeply golden and soft, stirring every 10 minutes.
When onions are about halfway done, preheat oven to 425°F, or according to package instructions. Spread half a bag of frozen French fries in a single layer on a baking sheet. Roast until golden and crispy, flipping halfway through (about 15-20 minutes in total).
Once onions are caramelized, stir in beef broth, balsamic glaze, thyme, and black pepper. Simmer for 5-7 minutes until slightly reduced and saucy. Remove from heat and stir in ¼ cup Boursin.
Season fries with Old Bay seasoning, then top with shredded gruyere cheese. Add French onion mixture to the fries, then finish it off with more crumbled Boursin, a swirl of balsamic glaze, chopped parsley, and thinly sliced serrano.

- Don't be intimidated by that heaping pile of onions - they'll cook down to practically nothing!
- Thin, uniform slices are best for caremlizing as they will cook down evenly with less risk of some pieces burning.
- I like to cut the onions into rings, but you can dice or slice them however you wish, as long as they're consistent!

- Resist the urge to rush the process! True caramelization takes time but adds major depth to the flavor.

- Fries are best when hot and crispy, so don't let them sit too long after topping them off!

- If you want, you can broil your assembled fries for 1-2 minutes after adding the toppings to get the cheese nice and melty and reheat the fries if they've cooled off.