---
title: French Onion Burgers
source:
  name: HelloFresh
  url: https://www.hellofresh.com/recipes/french-onion-burgers-5b16f897ae08b55b6a4a4892
servings: 2
prep time: 10 minutes
cook time: 20 minutes
time required: 30 minutes
difficulty: Easy
allergens:
  - Milk
  - Wheat
tags:
  - American
  - Burgers
  - Quick
  - Comfort Food
  - Beef
rating: 4.0
rating_count: 6600
source_chef: Recipe Development Team
review_highlights:
  - theme: Flavor
    text: The French Onion Burgers were delicious, with the kale chips adding a surprising and enjoyable element to the meal.
image: "https://images.recipes.furrysalamander.com/french-onion-burgers.avif"
---
@yellow onion{1%unit}
@kale{1%bunch}
@thyme{2%sprigs}
@beef stock concentrate{1%unit}
@gruyère cheese{2%oz}
@flour{1%tbsp}
@milk{½%cup}
@nutmeg{1%pinch}
@ground beef{10%oz}
@brioche buns{2%units}
@olive oil{3%tbsp}
@sugar{1%tsp}
@butter{1%tbsp}
@salt{1%pinch}
@black pepper{1%pinch}
@water{¼%cup}

Wash and dry all produce. Preheat oven to 350 degrees. Halve, peel, and thinly slice yellow onion. Remove stems and large ribs from kale, then tear leaves into bite-sized pieces. Toss kale on a #baking sheet{} with a drizzle of olive oil and a pinch of salt and black pepper. Bake in oven until crisp ~{10%minutes}. Keep an eye on them as they can burn quickly.

Heat a drizzle of olive oil in a #large pan{} over medium heat. Add yellow onion and thyme sprigs. Cook, tossing, until soft and browned ~{7%minutes}. Stir in beef stock concentrate, sugar, and water. Simmer until onion is jammy ~{2%minutes}. Remove and discard thyme sprigs. Remove onion from pan and set aside. Wipe out pan.

Meanwhile, grate gruyère cheese on large holes of a #grater{}. Melt butter in a #small pot{} over medium heat. Add flour and stir until lightly toasted ~{1%minute}. Slowly whisk in milk, then simmer until thickened ~{1%minute}. Season with nutmeg, salt, and black pepper. Set aside off heat.

Shape ground beef into two evenly sized patties (slightly larger than the buns). Season all over with salt and black pepper. Heat a drizzle of oil in the pan used for onion over medium-high heat. Add burgers and cook until just shy of desired doneness ~{3%minutes} per side. Sprinkle cheese on top of each burger, cover pan, and cook until cheese melts ~{1%minute}.

While burgers cook, split brioche buns in half and place on a baking sheet. Toast in oven until golden ~{2%minutes}.

Spread béchamel onto buns, then fill with burgers and caramelized onion. Serve with kale chips on the side.