Make the crust and roll it out, or use a store bought crust. If using a store bought crust on the grill, roll it out and place it on a flat surface in the freezer for 15-20 minutes, then transfer it directly to the grill.
Place the crust directly on the grill, over the lowest heat possible. Spread the ranch dressing over the top, then add the diced tomatoes, diced avocado, diced chicken and top with the cheese. Let cook on the grill for 10-12 minutes.
Don't overcook, as you run the risk of burning the bottom of the crust.
Carefully slide the grilled pizza from the grill onto a large cutting board or large baking sheet. Slice.
Serve Grilled Pizza with Chicken, Tomatoes and Avocado and a side of fresh fruit or carrot sticks.