Cut ham into 1/4-inch strips about 3 inches long. Cut each tomato into 8 wedges, and cut green and red peppers into 1/4 -inch wide strips. Cut onion and squashes into 1/4-inch slices. Heat oil in a large skillet over high heat. Add peppers, onion, squashes, and ham, and cook for about 5 minutes, stirring constantly. Reduce heat to medium; add chicken broth, basil, salt, and pepper. Cook until vegetables are crisp-tender, about 5 minutes. Add tomato wedges, and continue cooking until tomatoes are heated through.