Place the loaf of bread on a board and with a sharp knife, cut a large circle in the top of the bread, about 1-inch in from the edge, creating a ?lid?. Remove lid and pull out insides of bread from both base and lid, creating a bread ?shell?. (Reserve pulled-out bread for breadcrumbs or to feed the birds!). Spread about 2/3 of the pesto sauce over the inside of the bread base, covering as evenly as possible. Spread the remaining pesto on the underside of the bread lid. Layer 1/3 of the sliced meat in the bottom of the bread base, tucking it into the sides. Top with 1/2 of the sliced cheese, then 1/2 of the peppers, then half the tomato slices. Repeat layers, ending with the final 1/3 of the meat on top. Be sure to tuck meat, cheese, and vegetables into the sides of the bread base as well as in the center.
Replace the bread lid so it lines up with the cut marks. Wrap the sandwich in plastic or a bandana, sealing tightly so it holds together. To serve, cut the sandwich into 4 wedges with a sharp knife.