Smashed Burgers with Caramelized Onions and Chili Mayo

Ingredients

• 500 g Beef chuck mince (Divide into 8 equal balls.)
• Salt (For seasoning the beef and to taste.)
• Black pepper (For seasoning the beef.)
• 8 Cheddar cheese slices (One slice per patty.)
• 4 Hamburger buns
• 4 Large yellow onions (Thinly sliced.)
• 2.5 tbsp Butter or neutral oil (Use butter or oil to cook the onions.)
• 1 tsp Salt (For the caramelized onions.)
• 1 tbsp Sugar (Added near the end of onion cooking.)
• 2 dl Mayonnaise (For the chili mayo.)
• 1.5 tbsp Harissa paste (Use 1–2 tablespoons, according to desired heat.)
• 1 tbsp Honey
• 1 tsp Dijon mustard
• 2 cloves Garlic (Grated.)
• Salt (To taste in the chili mayo.)
• Pickles (For assembly, to taste.)

Steps

1. 1

   Thinly slice the onions. Keep the slices fairly even so they cook at the same rate.

2. 2

   Heat the butter or oil in a large skillet over medium-low heat. Add the sliced onions and 1 teaspoon salt.

3. 3

   Cook the onions slowly for 30–45 minutes, stirring occasionally, until very soft, deeply golden, and sweet-smelling. Lower the heat if they begin to brown too quickly.

4. 4

   Add the sugar and cook for 5 minutes more, stirring, until the onions are glossy and richly caramelized. Set them aside.

5. 5

   Make the chili mayo by combining the mayonnaise, harissa paste, honey, Dijon mustard, and grated garlic in a bowl.

6. 6

   Season the chili mayo with salt to taste, then refrigerate it while preparing the burgers.

7. 7

   Divide the beef mince into 8 equal portions and gently roll each portion into a loose ball. Do not overwork the meat.

8. 8

   Heat a heavy skillet, cast-iron pan, or griddle over high heat until extremely hot.

9. 9

   Place the beef balls in the hot pan, working in batches if necessary. Put a piece of baking paper over each ball and press it firmly with a sturdy spatula, small saucepan, or burger press until the meat is very thin.

10. 10

    Remove the baking paper. Season the patties with salt and black pepper, then cook until the underside develops a deeply browned, crisp crust and the edges look lacy, about 1–2 minutes.

11. 11

    Flip each patty and immediately place one cheddar slice on top. Cook until the second side is browned and the cheese is melted, about 1 minute. Repeat with the remaining patties.

12. 12

    Toast the hamburger buns cut-side down in the hot pan or on the griddle until lightly crisp and golden.

13. 13

    Spread chili mayo over the toasted bun halves.

14. 14

    Build each burger with two cheese-topped smashed patties, caramelized onions, and pickles. Finish with the top bun and serve immediately.

Notes

The source specifies butter or oil for the onions and gives ranges for harissa and onion-cooking time. For food safety, cook ground beef thoroughly; the patties are very thin and cook quickly. Serve immediately for the crispest edges.

Nutrition per serving

• main
• burgers
• American
• beef
• cheesy
• spicy
• caramelized onions
• skillet