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Lamb Sirloin with Roasted Garlic Chimichurri Sauce | Keto & Paleo Easter Recipe

This lamb sirloin with Argentinian Chimichurri Sauce makes for a perfect Keto and Paleo Easter Dinner or Easter Lunch!  Adding oven-roasted garlic to the chimichurri sauce takes this Argentinian classic to the next level.

Course main
Cuisine American, European
Keyword homemade chimichurri sauce, lamb recipe for Easter, lamb sirloin
Prep Time 15 minutes
Cook Time 1 hour
Resting time 10 minutes
Total Time 1 hour 15 minutes
Servings 4 people
Calories 300 kcal
Author Kiki Johnson


  • 2 pounds boneless lamb sirloin
  • salt, pepper

For the chimichurri sauce

  • 1/2 head garlic you can use up to a whole head
  • 1 bunch fresh parsley
  • 1/2 bunch fresh cilantro
  • 2 tsp dried oregano or 1/2 bunch fresh
  • 3 tbsp vinegar
  • 1/2 cup olive oil
  • 1/4 tsp cayenne pepper
  • 1/4 tsp cumin
  • 1/2 tsp freshly ground black pepper
  • 1/2 tsp salt + more to taste


For the roasted garlic chimichurri sauce

  1. Preheat the oven to 400°F and set a rack in the middle position.

    Peel off some of the outer layers around the garlic. Make sure to leave the head itself intact with all the cloves connected. Trim about 1/4 inch off the top of the head of garlic to expose the tops of the garlic cloves.

    Drizzle with 1 tsp of olive oil over the exposed tops of the garlic, wrap in aluminium foil and roast in the oven for 40 minutes.

    Begin checking the garlic after about 40 minutes. We are looking for a completely soft centre when pierced with a paring knife. You can continue roasting until deeply golden for a more caramelized flavour — check the garlic every 10 minutes to avoid burning.  Let the garlic cool slightly.

    NOTE: Separating the head of garlic into individual cloves will make the garlic roast more quickly. Leave the unpeeled garlic cloves intact, toss with olive oil, and roast in a foil packet until soft.

  2. Wash herbs and dry them well. Shave parsley leaves from the stems and save stems for a soup. Chop herbs very coarsely. Combine herbs, roasted garlic ( Press on the bottom of a clove to push it out of its paper), vinegar,  oil, and spices in a blender. Pulse blender and make pauses to scrape down the sides using a rubber spatula. Repeat pulsing and scraping process until thick sauce forms, about 12 times. Do not feel tempted to add more liquid. In the beginning, the mixture will seem too dry, but as you keep on pulsing, the herbs will release their natural juices and everything will come together to a smooth, green sauce. Season with more salt to taste.

For the lamb

  1. Preheat oven to 200 C. Preheat a grill pan over medium-high heat until very hot.  In the meantime, use a sharp knife to score the fat caps every inch; rotate the lamb 90° and repeat to form a crosshatch pattern. Season the meat generously all over with salt and pepper.

  2. Transfer the lamb fat side down to the grill pan and cook until the fat renders a bit and the fat side is well browned about 3 to 4 minutes. Using tongs, turn the meat and cook, turning occasionally, until browned all over. Transfer onto a baking sheet and let sit in the oven with a meat thermometer inserted into the centre. Once it reads 145° (medium-rare), take it out, wrap it in aluminium foil and let rest.

  3. Once the meat has rested for at least 10 minutes, cut it into slices and drizzle with the chimichurri sauce. 

Recipe Notes

Leftover chimichurri sauce keeps in the fridge for at least 2 weeks.