Heat grill or grill pan up to medium-high heat.
Place olive oil in a pan on the stovetop. Add in sliced onion and cook on medium-low until softened and brown.
Meanwhile, preheat oven to 450ºF. Cut up sweet potatoes and throw onto a cookie sheet. Toss with olive oil and sea salt and pepper. Bake in the oven for 20-25 mins.
In a medium sized mixing bowl, combine together turkey, grated onion, grill seasoning, BBQ sauce, Worcestershire, garlic, jalapeño, cheese and bread crumbs. Shape into 4 - 5 patties. Grill until no longer pink inside, 165 degrees F inside.
Quickly make sauce by combining mayo, honey mustard, horseradish and cayenne. Can double or triple sauce amount easily. Serve with burgers and sweet potato fries.
Serve spicy turkey burgers with a pile of caramelized onions on top and a bit of ketchup. Side dish of sweet potato wedges and spicy mayo sauce. Enjoy!