Heat oven to 350°F. Lightly spray large cookie sheet with CRISCO® Original No-Stick Cooking Spray.
Cut each bell pepper lengthwise into quarters, making 8 pieces; remove stems, seeds and membranes. In 2-quart saucepan, heat 4 cups water to boiling. Add bell pepper pieces; cook 5 minutes. Drain well on paper towels; set aside.
Meanwhile, in 10-inch skillet, cook beef over medium heat 8 to 10 minutes, stirring occasionally, until thoroughly cooked; drain. Stir in taco seasoning mix and salsa until well blended; set aside.
Separate dough into 8 biscuits. Place biscuits 2 inches apart on cookie sheet; brush with egg.
Press 1 pepper piece, skin side down, on each biscuit. Spoon heaping 1/4 cup beef mixture into each pepper, spreading to cover pepper evenly. Sprinkle each with 2 tablespoons cheese.
Bake 18 to 22 minutes or until cheese is melted and edges of biscuits are golden brown. Cool 5 minutes. Top each with 1 tablespoon sour cream.