Rice and Bean Wraps

2 tablespoons butter or butter flavor Crisco
1 (6.8 ounce) package Rice A Roni Spanish or plain rice
2 cups water
1 (16 ounce) jar salsa
1 can black or kidney beans, washed and drained
1 can Mexicorn, drained
8 (8-inch) flour tortillas, warmed
Shredded Cheddar cheese or Velveeta (optional)
Sour cream (optional)

In large skillet over medium-high heat, saut