French Onion Avocado Burger and Fries Recipe


Make your next get-together plant-based and delicious with this easy French Onion Avocado Burger & Fries recipe by Chef Matthew Ridgway. This French twist on an American classic features an Impossible Burger Patty and a side of cottage fries that will have your mouth watering. Chef Matthew has more than 22 years of experience in the culinary industry and he knows better than anyone that turning your favorite, greasy meal into a plant-based recipe is easier (and tastier) than you think. To get started, check out the ingredient list to make sure you have everything you need. If you get stuck or want extra tips on how to give this meal an extra kick, take a look through Chef Matthew's how-tos for this class. Bon Appétit!

What You'll Need

  • Cutting Board
  • Global Chef's Knife
  • Le Creuset Dutch Oven
  • de Buyer Nonstick Pan


  • 1 tsp ketchup
  • 1 tbsp Maille Dijon Mustard
  • 1/4 cup of mayonnaise
  • 1 tsp steak sauce
  • 1/4 tsp Worcestershire sauce
  • Parmesan cheese
  • Italian seasoning
  • Smoked Paprika
  • Salt
  • Pepper
  • Onions
  • Gruyere cheese
  • Avocado
  • Impossible Burger Patties
  • Martin's Potato Seeded Potato Rolls
  • Olive Oil


  1. Preheat the oven to 350. Line a non-reactive baking sheet with aluminum foil.  
  2. Make the cottage fries: Wash potatoes, cut them into 4 sections and season with Italian seasoning, salt, pepper, smoked paprika, extra virgin olive, and parmesan shaker cheese.
  3. Spread the cottage fries onto the pan and bake at 350 until you can pierce the potato with a knife and it comes clean. About 25 minutes 
  4. Begin building the Gruyere Avocado Burger.
  5. Make the sauce: Mix everything together in a glass bowl: ¼ cup of Duke's mayonnaise, 1 teaspoon Heinz ketchup, 1 tea A-1 steak sauce, ¼ tsp worcheshire sauce, 1 tablespoon of Maille dijon mustard, salt and black pepper to taste.
  6. Make the Caramelized Onions: 2 onions thinly sliced on a Benriner mandoline. In a Le Creuset dutch oven, add 1 tbsp of olive oil and 1 tbsp of butter to medium heat until the butter begins to foam. Add the onions, turning them slowly once in a while until they're soft. Gradually raise the heat and season as you cook. Once the onions are completely caramelized after 5 minutes turn down the heat to make sure they're equally browned throughout. Set aside and let cool slightly.
  7. Cut the avocado in half, take out the pit, and use a spoon to remove the inside of the avocado.
  8. Slice three times on a bias and season with salt and pepper. Add a squeeze of lime juice.
  9. Cook the Impossible Burger Patties: Season patties with salt and pepper. Heat a Dubuyer cast iron steel pan with oil or beef fat until it smokes then add the first side of the burger. Do not move the burger and let the bottom form a crust. Flip the burger and repeat the process. This skillet burger will cook until about medium well. 
  10. While the burger is being flipped, open the Martin's Potato seeded rolls. Place a dollop of sauce on both sides of the bun. Smear the sauce into the bun.
  11. Place the burger patty on the bottom bun and place a pile of caramelized onions on the burger.
  12. Top with the avocado. And top with the seeded part of the bun.
  13. Serve with cottage fries.

Matthew Ridgway brings more than 22 years of experience in the culinary industry to his role as executive chef at Cooks & Soldiers. From working in fine dining restaurants across the U.S. and France to running his own charcuterie business, Ridgway boasts an extensive background and unique perspective to the team.

Check out Matthew Ridgway's profile to learn more about the Chef.


How-To Caramelize Onions

Chef Matthew Ridgway teaches you the proper way to caramelize onions using the Le Creuset Dutch Oven.


Before starting the class, you'll want to make sure you're up to speed.


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