Spanish-Style Lamb Burgers with Romesco Sauce

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Burgers on a whole new level, with loads of flavor from caramelized onions and a Romesco sauce that you will want to use on absolutely everything.

Spanish Lamb Burger with Romesco Sauce and Caramelized Onions on a plate with chips.

A burger made with ground lamb is a burger with personality. Big on flavor, juiciness, and tenderness. This version of lamb burgers is spiked with onions, garlic, olives, and smoked paprika. If you want to take them to the next level, top them with slightly melted Manchego cheese, a pile of beautifully browned caramelized onions (grilled onions are another option), and creamy, smoky Romesco Sauce, a classic Spanish condiment.

When my lamb-loving son Charlie ate one of these burgers for the first time, he said, “I think this is one of the best things you have ever made.” ”Well, all right, all right, all right!” I’ll be laying in a supply of ground lamb this summer for sure.

I’ve made a few of these Spanish-style burgers on the stovetop and also taken this burger al fresco to the grill. A pile of chips on the side of a burger is never a bad thing (and those delicious little Spanish potato sticks would be amazing). Also, consider pairing this with Simple Couscous Salad or Tomato, Zucchini, and Bulgur Salad for a mid-summer gathering. And big fat glasses of beer, Agua Fresca or Red Sangria.

Spanish Lamb Burgers with Romesco Sauce and Caramelized Onions and chips on blue plate.

This Spanish Lamb Burger recipe takes burgers to a whole new level; with loads of smoky flavor, caramelized onions, and a Romesco sauce you will want to use on absolutely everything.

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Spanish-Style Lamb Burger Ingredients

For the lamb burgers

  • Olive oil – Used to sauté up the onions.
  • Onions – Half the onions get mixed into the burger meat, and the rest are used as a topping.
  • Minced garlic – Just a little. I wanted to complement the flavor of the lamb but not overpower it.
  • Ground lamb – Ground lamb is just as easy to work with as ground beef—and it’s very affordable as well.
  • Spanish green olives – I recommend manzanilla olives; pimentos inside are a-ok!
  • Smoked paprika – Regular paprika is fine if you don’t have smoked.
  • Manchego cheese – A classic Spanish cheese, but you can use whatever cheese you like on a cheeseburger.

For the Romesco-style sauce

Romesco sauce typically has nuts in it, but in this romesco-ish recipe, there are no nuts because I’m allergic. I used this nut-free Romesco sauce on quite a number of things post-burger: a crostini slathered with some sauce and topped with leftover caramelized onions was one of the winning uses.

  • Mayonnaise – Mayo makes the perfect creamy base for this sauce.
  • Roasted red peppers – You can use jarred red peppers or make them yourself.
  • Smoked paprika – Using the same spices in the burgers and the sauce really pulls the whole thing together.
  • Cayenne pepper – Adds a bit of subtle heat.
  • Sherry vinegar or lemon juice – The acidity is key to balance out the flavors in the sauce.
  • Buns – I used brioche buns, but regular hamburger buns are fine.
Person holding a Spanish Lamb Burger with Romesco Sauce and Caramelized Onions missing a bite.

Lamb Burger Toppings

The caramelized onions do double duty. You sauté up a batch of sliced onions and then chop up a small amount of them to be blended into the meat mixture. The rest are saved for heaping on top of the burgers, along with a generous slather of Romesco sauce. (If it’s summer, think about Grilled Onions.)

And the burgers themselves can be served up with no cheese, or turned into cheeseburgers with a handful of Manchego cheese sprinkled over the top until melty.

How to Make Spanish Lamb Burgers with Romesco Sauce

  1. Cook the onions: Sauté all the onions until soft, then set some of them aside to use as a topping. Chop the rest of the onions up and cook a bit more with the garlic.
Pan with sauteing onions.
  1. Form the burgers: Mix the cooked onion and garlic together with the lamb, olives, smoked paprika, salt, and pepper. Then make them into patties. Don’t miss these tips on making perfect burger patties!
Forming hamburger patties.
  1. Make the sauce: Combine the mayonnaise, roasted peppers, paprika, vinegar or lemon juice, salt, and pepper. Blend them together until smooth.
  2. Cook the burgers: You can cook the burgers in a skillet or on the grill. Add the cheese at the end, if desired, and let it melt.
Grilling cheeseburger.
  1. Assemble: Toast up your buns and top with a burger patty, some of the sauce, and some sautéed onions.
Spoon scooping Romesco sauce and caramelized onions onto a Lamb Burger.

What to Serve With Spanish Lamb Burgers

Spanish Lamb Burgers with Romesco Sauce and Caramelized Onions on blue plate.

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5 from 1 vote

Spanish-Style Lamb Burgers with Romesco Sauce

Burgers on a whole new level, with loads of flavor from caramelized onions and a Romesco sauce that you will want to use on absolutely everything.
Prep Time: 20 minutes
Cook Time: 20 minutes
Total Time: 40 minutes
Servings: 6 People
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Lamb Burgers

  • 1 tablespoon olive oil
  • 2 large onions (halved and sliced)
  • 1 teaspoon minced garlic
  • 2 pounds ground lamb
  • 2 tablespoons minced Spanish green olives (such as manzanilla; pimentos inside are a-ok!)
  • ½ teaspoon smoked paprika (or regular)
  • 1 cup grated Manchego cheese (optional)

For the Romesco-ish Sauce

  • ½ cup mayonnaise
  • ¼ cup chopped roasted red pepper (jarred or homemade)
  • ¼ teaspoon smoked paprika (or regular)
  • ¼ teaspoon cayenne pepper
  • 1 tablespoon sherry vinegar or lemon juice
  • Kosher salt and freshly ground pepper (to taste)
  • 6 buns (regular hamburger or brioche buns)


  • Heat the olive oil in a medium skillet over medium heat, and add the onion. Sauté for about 7 minutes until the onion is softened and golden brown. Remove about 2/3 of the sautéed onion and set aside. Chop the rest of the onion, then return to the pan over medium heat. Add the garlic to the pan and sauté for one more minute until you can smell the garlic. Remove to a large bowl and cool.
  • When the onion and garlic mixture is cool, add the lamb, olives, 1/2 teaspoon smoked paprika, salt, and pepper. Use your hand to mix gently but thoroughly. Form the mixture into 6 even patties, and use your thumb to make an indent in the middle of the burger so that as it cooks and puffs in the middle it ends up flat and not rounded.
  • Make the sauce. Combine the mayo, roasted peppers, paprika, cayenne, sherry vinegar or lemon juice, and salt and pepper in a small food processor or blender. Process until smooth.
  • Either preheat the grill to medium high, or very lightly oil a nonstick skillet and heat over medium high heat. Cook the burgers wither in the pan or on the grill for about 4 minutes per side, until they have reached the desired doneness. The USDAS recommends an internal temperature of 160°F . Top with Manchego at the end if desired and either close the grill lid or place a lid over the pan until the cheese starts to melt.
  • Toast the buns if desired, again either on the grill or in a pan on the stovetop. Place a burger on the bottom of each bun, top with the romesco-ish sauce, and then top with the reserved sautéed onions. Serve hot.


The burgers themselves can be served up with no cheese, or turned into cheeseburgers with a handful of Manchego cheese sprinkled over the top until melty.


Calories: 796kcal, Carbohydrates: 26g, Protein: 35g, Fat: 61g, Saturated Fat: 23g, Cholesterol: 138mg, Sodium: 660mg, Potassium: 452mg, Fiber: 2g, Sugar: 5g, Vitamin A: 314IU, Vitamin C: 6mg, Calcium: 311mg, Iron: 4mg
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About Katie Workman

Katie Workman is a cook, a writer, a mother of two, an activist in hunger issues, and an enthusiastic advocate for family meals, which is the inspiration behind her two beloved cookbooks, Dinner Solved! and The Mom 100 Cookbook.

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