Cut zucchini in medium slices and toss in 1/3 cup olive oil.
Place on medium high grill.
Sprinkle with 1/4 tsp seasoning.(If your pizza seasoning doesn't have garlic salt in it sprinkle about 1/8 tsp garlic salt on zucchini; or regular salt if you prefer).
Grill until soft to touch.
While grilling zucchini place diced tomatoes in a 8x8 casserole dish and sprinkle with 1/4 tsp seasoning (Add garlic or regular salt here as well) When zucchini is done place on top of tomatoes. Put mozzarella on top-drizzle with remaining olive oil and sprinkle 1/4 tsp seasoning on top.
Bake in 350 degree oven until cheese is melted and bubbly.