Place a cast iron skillet on the grill.  Heat the oil and sauté garlic and onion until tender.  Add a pinch of salt, to taste.  Cut eggplant into thin slices and brush lightly with olive oil mixture, reserve the rest of the oil for later.  Grill eggplant for 2 minutes on each side then remove from heat and set aside.  Slice roasted red peppers, artichoke hearts, and fresh mozzarella into thin, flat slices.  Slice chicken sausage into thin-slices lengthwise. 

Slice bread and brush one side of each piece lightly with the oil mixture. 

Assemble paninis by placing a slice of bread on the grill oiled side down.  Then layer chicken sausage, eggplant, roasted red peppers, artichokes, 4 leaves of fresh basil, and a slice of mozzarella.  Drizzle each sandwich with the rest of the oil mixture and sprinkle ground black pepper and sea salt to taste.  Top the sandwiches with a slice of bread, oiled side up.  Press firmly on the top of each Panini with a heavy object, such as the cast iron skillet, until it begins to sizzle.  Grill the paninis over medium heat for 4 minutes on each side, or until the bread is toasted and the cheese is melted.  Remove from heat, slice in half, garnish with fresh basil and enjoy!