Skin the sausage (if necessary). Brown sausage and hamburger in a large skillet. Drain fat. Over low heat, add Velveeta until it's thoroughly melted, and stir thoroughly. Spread a small spoonful of the mixture on each slice of the Party Rye and place on a cookie sheet. Freeze for at least 2 hours. After that, you can remove them from the cookie sheets and put them in a freezer bag for up to 2 weeks! To serve, just place the frozen "pizzas" on a cookie sheet and bake at 180ºC or about 15 minutes or until hot. Serve immediately. Makes about 40.