Bring out the best in these luscious lamb sliders with homemade aioli and sweet onion jam.

Preparation

Melt the butter in a small sauce pot over medium-low heat. Add onions and cover with a tight-fitting lid. Allow the onions to cook covered for 10-15 minutes, then stir and continue to cook covered for an additional 20 minutes, until the onions have released all of their liquid and are very soft. Cook uncovered for an additional 15-20 minutes, or until all of the liquid has evaporated and the onions have caramelized and have the consistency of jam. 

While the onions are cooking, sweat the shallots and garlic in a pan with olive oil. When they are soft, add the saffron, cumin and paprika. Cook for 1 minute stirring constantly. Remove from heat and cool to room temperature. When cool, mix with mayonnaise, lemon zest, ⅛ teaspoon salt and ⅛ teaspoon black pepper. 

Form the lamb into 4 patties that are about ½ inch larger than the buns. Season with salt and pepper and grill for approximately 2 minutes on each side for medium doneness. Allow to rest for 5 minutes before assembly. 

Toast slider buns on the grill. To assemble, spread the onion jam on the bottom bun and the aioli on the top bun. Place the burger patty on the bottom bun topped with tomato and arugula, then finish with the top bun.