1. In 3-quart casserole or bowl, combine onion, garlic, and salad oil; cover with casserole lid or large plate. Cook at high (100% power) 5 to 6 minutes, stirring once, until onion is tender. Stir in chili powder; cover and cook 1 minute longer. Stir in flour until blended. Stir in catchup, molasses, vinegar, salt, and ground red pepper until smooth.
2. With sharp knife, cut pork shoulder blade roast into matchstick-thin strips. Add pork strips to catchup mixture in casserole; mix well.
3. Cover casserole. Cook at high 8 to 10 minutes, until mixture begins to boil, stirring every 3 minutes. Then cook at medium (50% power) 15 to 20 minutes longer, stirring after 10 minutes, until meat is tender and mixture thickens slightly.