Add the egg yolks, ground cumin, salt, siracha, and dijon mustard in a food processor. Start pulsing the food processor and slowly stream in the canola oil. Spoon the mayo mixture into a separate bowl, and fold in the lemon juice. Set aside in the fridge if not immediately using.
If you aren’t up to making this mayo from scratch, mix store-bought mayo with lemon juice, cumin, salt, siracha, and dijon.
Burger Instructions
First, make the burger patties by mixing the ground lamb, salt, pepper, paprika, and ground cumin.
Form into 4 patties, set on a plate and loosely drape a piece of plastic wrap on top. I suggest letting it rest in the fridge for at least 8 hours, or up to 24 hours, to intensify the flavours seriously.
Make the cumin mayo.
Make the caramelized onion – In a large skillet, drizzle with olive oil, add the sliced red and yellow onion. Sprinkle with salt, and drizzle with a little more olive oil on top; toss to make sure all the onions are coated with olive oil. Cook at medium-low heat for about 20 to 30 minutes. Set aside.
Toast the brioche buns on the grill. Set aside. Then, grill the lamb burger patties until desired doneness (I like my lamb medium). Add the feta on top of the burgers right before they are done.
Spread the cumin mayo on the bottom of the toasted brioche bun, add the lamb topped with cheese, caramelized onion, a small handful of arugula, and the top of the bun that has more cumin mayo spread on it.
Enjoy with a light Greek salad or just some shoestring fries with cumin mayo to dip them in.