PreparationFor salsa: Whisk first 3 ingredients in medium bowl to blend. Mix in next 4 ingredients. Season salsa to taste with salt and pepper. Do ahead: Can be made 8 hours ahead. Cover and chill. For burgers: Stir shallot, cilantro, jalapeño, garlic, salt, black pepper, paprika, and cumin in large bowl to blend. Add lamb and mix gently to combine. Shape mixture into four 1/2-inch-thick patties. Arrange on small baking sheet. Do ahead: Can be made 8 hours ahead. Cover and chill. Spray grill rack with nonstick spray and prepare barbecue (medium-high heat). Grill buns, cut side down, until golden, about 2 minutes; transfer to work surface. Place lettuce and large spoonful of salsa on each bun bottom. Grill burgers until slightly charred and cooked to desired doneness, about 4 minutes per side for medium-rare. Place 1 burger on each bun. Top each with mayonnaise and bun top. Serve with remaining salsa.
PreparationFor salsa: Whisk first 3 ingredients in medium bowl to blend. Mix in next 4 ingredients. Season salsa to taste with salt and pepper. Do ahead: Can be made 8 hours ahead. Cover and chill. For burgers: Stir shallot, cilantro, jalapeño, garlic, salt, black pepper, paprika, and cumin in large bowl to blend. Add lamb and mix gently to combine. Shape mixture into four 1/2-inch-thick patties. Arrange on small baking sheet. Do ahead: Can be made 8 hours ahead. Cover and chill. Spray grill rack with nonstick spray and prepare barbecue (medium-high heat). Grill buns, cut side down, until golden, about 2 minutes; transfer to work surface. Place lettuce and large spoonful of salsa on each bun bottom. Grill burgers until slightly charred and cooked to desired doneness, about 4 minutes per side for medium-rare. Place 1 burger on each bun. Top each with mayonnaise and bun top. Serve with remaining salsa.