Roughly chop 4 garlic cloves with 1/2 tsp salt, using flat side of large knife, mash garlic into a paste. Transfer to a bowl, mix with beef, lamb, pork and half the paprika, savory, cayenne, GRATED onion, 2 tsp salt and 2 tsp pepper. Add soda water; bea with a spoon till tacky. Knead with with your hands for 3 minutes; cover and refrigerate 2 hours.
Knead mixture once more for about 1 minutes, then shape into sixteen 3 long sausages. Transfer to a sheet pan. Cover and refrigerate 1 hour.
Meanwhile, make the sauce. Heat broiler, with rack 6 inches from broiler element. Arrange peppers and eggplant on foil lined baking sheet in a single layer, cut sides down. Rub with 1 Tablespoon olive oil, sprinkle with salt. Broil, turning once, till softened and somewhat charred, 14-15 minutes. Remove and discard skins from peppers. Scoop flesh from eggplant, discard skin and largest seeds. Pulse eggplant and 4 tablespoons olive oil in food processor with remaining garlic to make a coarse puree; transfer to a bowl. Puree peppers, add to eggplant and stir in remaining paprika, vinegar, sugar and salt and pepper to taste. Cover and set sauce aside.
Heat remaining olive oil in large skillet over medium high heat. Cook sausages, turning occasionally, till browned, 6-8 minutes. Serve with sauce, pita bread and sour cream.