Heat oven to 425°F. Remove 1 pie crust from pouch; place flat on ungreased 14-inch pizza pan or cookie sheet.
In 10-inch skillet, heat oil over medium-high heat. Add onion and bell peppers; cook 5 minutes, stirring occasionally, until tender. Stir in chicken and fajita seasoning. Spoon mixture onto crust to within 1 inch of edge. Spread 1/2 cup dip over chicken mixture. Brush edge of crust with water.
Remove second crust from pouch; place flat over filling. Press edge firmly to seal. Brush top with beaten egg.
Bake 20 to 25 minutes or until deep golden brown. After 10 to 15 minutes of baking, cover crust edge with strips of foil to prevent excessive browning. Cut into wedges. Garnish with sour cream and additional dip.