In a medium bowl, combine the first 5 ingredients. With 2 knives or your fingers, cut in the shortening until the mixture resembles coarse crumbs. Add the milk, stirring with a fork, just until the mixture holds together. With a large spoon, drop dumpling batter in 8 spoonfuls over the stew. Simmer over medium-low heat, covered, about 16 minutes, or until the dumplings are done.