GRILL DIRECTIONS: Heat grill. Heat chicken strips as directed on package.
Meanwhile, separate dough into 8 biscuits. Press each to form 5-inch round. Spray 1 side of each round with nonstick cooking spray. Place sprayed biscuit rounds, cheese, onions and warm chicken on tray for carrying to grill.
When ready to grill, place biscuit rounds, sprayed side down, on gas grill over medium-low heat or on charcoal grill 4 to 6 inches from medium coals. Cook 3 to 4 minutes or until bottoms are browned. Turn biscuits; top with cheese, onions and warm chicken. Cook an additional 2 to 3 minutes or just until cheese begins to melt. (By the time all are topped, first ones are done.)
To serve, top tostadas with lettuce, salsa and sour cream.