Heat the oven to 350°. Mix the ground beef, half of the onions, the bread
crumbs, 1/4 cup of the soup, the egg, thyme leaves, salt and pepper. Press
the mixture evenly against the bottom and sides of an ungreased 9-inch pie
pan. Turn the drained green beans into the meat line pan then spread the
remaining soup over the beans. Bake, uncovered, for 35 minutes. Sprinkle with shredded cheese, if using, then arrange the remaining onions on the top of the mixture and bake another 10
minutes. Cool for about 5 minutes, then cut into wedges and serve.