Let me start off with the suggestion of making the tzatziki sauce either a whole day ahead of time or a few hours ahead of time. While not TOTALLY necessary, the sauce just thickens the longer it's refrigerated, so it has more of an authentic consistency by the time you top it on the burger.
Second tip is to 100% follow my optional instructions for the portabella mushroom cap bun. It's magical. If you don't like shrooms though, then maybe don't do the portabella bun (womp womp). Ok that's it! I feel like the words "greek" "lamb" and "burger" are convincing enough to make this thang.
For the Portabella Mushroom Cap Bun
- 4 portabella mushroom caps
- Olive oil
For the Lamb Burgers
- 1 lb ground lamb
- 1 tbsp fresh mint, chopped
- 1 tbsp fresh rosemary, chopped
- 1 tbsp dried oregano
- 1/4 tsp sea salt
- 1/4 tsp cracked pepper
For the Tzatziki Sauce
- 1/2 cup full-fat coconut milk
- 1/2 cup cucumber, chopped
- 1 tsp minced garlic
- 2 tbsp lemon juice
- 1 tsp dried dill
- 1 tbsp coconut vinegar
- Salt and pepper to taste
- Male the tzatziki sauce ahead of time. Whisk all the ingredients together and refrigerate until thickened - at least 6 hours, but the longer, the better.
- If not using the bun, disregard this step and skip to 3. Preheat the oven to 400. Remove the stems of the mushroom caps (easy by hand) and use a spoon to scrape out the inner gills. Brush the caps with olive oil on both sides and place on a foil-lined baking tray. Bake for 15-20 minutes, or until the mushrooms have softened.
- Combine all the burger ingredients and form 4 patties.
- Toss the burgers on the grill and cook to your preference. I like a medium rare inside so my burgers aren't on the grill long. You can also cook these in a large skillet with a tbsp of cooking fat (cook for 3-7 minutes per side, depending on how rare or well-done you like your burgers).
- Place a burger inside of each mushroom cap and top with 1-2 tbsps of tzatziki sauce. Feel free to also top each burger with an additional mushroom cap, like I did!