1. For filling: Let cream cheese stand at room temperature for 30 minutes to soften. In a large mixing bowl, beat the cream cheese with an electric mixer until smooth. Add the Monterey Jack cheese and 8 ounces sour cream; beat until combined. Add the eggs all at once, beating on low speed until mixture is just combined. Stir in salsa and chile peppers.
2. Pour filling into a 9-inch springform pan. Place pan in a shallow baking pan. Bake the cheesecake in a 350 degree F oven for 35 to 40 minutes or until center of cheesecake appears nearly set when shaken. Place pan on a wire rack.
3. Dollop remaining carton of sour cream over top of hot cheesecake; let stand about 1 minute to soften, then carefully spread over top. Cool cheesecake thoroughly. Cover and refrigerate cheesecake for 4 to 24 hours before serving.
4. To serve, remove the sides of the pan. Dollop the top outside edge of the cheesecake with avocado dip. If you like, stir additional avocado into the dip. Sprinkle cheesecake with chopped tomato. Garnish with cilantro, if you like. Serve with tortilla chips, melba toast or crackers. Makes 20 servings.