Tortellini without stock

1 (9 ounce) package cheese-filled tortellini 1 tablespoon oil 1 tablespoon butter 3 -5 garlic cloves , peeled and minced 1 cup half-and-half 1/2 cup chicken[...]

18 -19 ounces cheese tortellini 8 ounces good quality feta cheese , cut into 1/2-inch cubes 1 cup pitted black olives , broken into 1/4-inch to 1/2-inch[...]

2 medium potatoes 1 lb frozen mixed vegetables 1 lb cheese tortellini 1/4 cup margarine 1/4 cup all-purpose flour 2 cups milk 1/2 teaspoon salt pepper basil[...]