Place the sliced vegetable and rosemary in a glass bowl and cover with white wine vinegar. Let sit at room temperature while you prepare the rest of the burger.
Drain excess vinegar and discard rosemary sprig.
Ajvar Sauce
Wrap whole eggplant in aluminum foil. Place directly on hot coals of a BBQ and add wood for extra smokiness. Alternatively, you can place in 425 degrees oven and roast that way. Roast the eggplant until it is soft and collapses.
Roast the red pepper over the open flame of gas stove. The skin will blister and turn black. Make sure all of the skin is blistered. Place warm pepper in a glass bowl and cover with plastic wrap. Let the pepper sit for about 10 minutes, then use a sharp knife and peel the skin off of the pepper. Scoop out the seeds and cut off the stem and discard.
Place eggplant, garlic, and rosemary in a food processor and pulse until smooth. Chop the pepper into chunks then add those to food processor and pulse until peppers are mixed in (small chunks are fine).
Salt & pepper to taste.
Montenegro Burger
Grill buns in oil or butter until lightly golden.
Divide the ground lamb into four portions and form patties. Combine the salt and smoked paprika and sprinkle evenly on all four patties.
Cook the lamb patties in olive oil over medium high heat until desired temperature. Add mozzarella slices to the burgers and cover the pan for a minute or so until cheese is melted. Place the patties on the grilled buns and top with Ajvar and Pickled Root Vegetables.