Pierce potatoes with fork. Arrange in spoke pattern on microwave-safe paper towel in microwave. Microwave on High for 12 to 14 minutes or until tender, turning potatoes and rearranging halfway through cooking. Cool 3 minutes.
Meanwhile, heat taco sauce with seasoned ground beef as directed on package.
To serve, cut potatoes in half lengthwise; mash slightly with fork. Spoon about 1/2 cup ground beef mixture over each potato. Top with Cheddar cheese, tomato and green onions.