Combine Jack, Swiss and Parmesan cheeses in a mixing bowl.
Drain artichokes and dice into small pieces.
Wash and cut spinach into 1-inch pieces and add to cheese mix.
In a separate mixing bowl combine the mayonnaise, Alfredo sauce, garlic and pepper. Mix until well-combined.
Pour mayonnaise mixture into cheese mix. Stir, gently but well, until well-mixed.
Drain sun-dried tomatoes of any oil or liquid. Dice into small pieces. Add to the mixture.
Heat cold dip mixture over medium heat in non-stick frying pan until hot and cheese is completely melted. Transfer to serving dish and serve with tortilla chips and sliced bread.