Preheat the oven to 350 degrees F.
Toss the onion slices with the oil and lightly season with salt and pepper. Arrange in a layer on a baking sheet and roast until tender and starting to color, stirring as necessary, 10 to 15 minutes. Remove from the oven and set aside.
Arrange the tomatoes, cut sides up, on the baking sheet. Season the cut sides lightly with salt and pepper. Roast until they have released most of their liquid and are slightly caramelized around the edges, about 1 hour. Remove the tomatoes from the oven and let cool slightly. Cut the tomatoes into thin strips.
Wrap the lavosh breads in aluminum foil and place in the oven to warm and soften. Remove from the oven.
Spread the roasted garlic and eggplant spread evenly on the lavosh breads, leaving a slight border along the edges. Arrange the sliced lamb then the tomatoes and onions over the bread and drizzle with the feta sauce. Sprinkle with the fresh basil. Roll tightly as though making a cigar, pressing as you go to keep the filling in place. Wrap tightly in plastic wrap and refrigerate for 30 minutes so it will be firm enough to slice. Cut each lavosh either in half (like a burrito), or on the bias into 1-inch sections. Serve additional feta sauce on the side for dipping, as desired.
Yield: 2 to 4 servings