In a 4-quart Dutch oven combine vegetables and the 1/2 cup water. Bring to boiling over medium heat. Meanwhile, microwave beef tips according to package directions. Add beef and Worcestershire sauce to vegetables. Reduce heat to low. Cook, covered, for 5 minutes or until vegetables are tender.
In a small microwave-safe bowl combine garlic and the 2 tablespoons water; cover with vented plastic wrap. Microwave on 100 percent power (high) for 1 minute; set aside. In a large microwave-safe bowl microwave potatoes on 100 percent power (high) for 8 to 10 minutes; stirring once halfway through cooking.
Peel and mash garlic. Add garlic, olive oil, salt, and pepper to potatoes; mash. Divide potatoes among four dishes; top with stew and sprinkle with oregano.