Preheat oven to 450°. Line cookie sheet with parchment paper.
In large microwave-safe bowl, combine cauliflower pearls and ¼ cup water; cover bowl with plastic wrap. Heat in microwave oven on high 12 minutes or until very tender; uncover and let stand 30 minutes. Place cauliflower in clean kitchen towel; squeeze until very dry.
In same bowl, stir garlic, egg whites, ¼ cup Oaxaca cheese, Cotija cheese, oil, salt, black pepper and cauliflower.
Press cauliflower mixture into 12-inch circle on prepared cookie sheet. Bake 24 minutes or until browned. Evenly top crust with marinara, remaining ½ cup Oaxaca cheese, turkey franks, turkey ham, bell pepper and mushrooms. Bake 7 minutes longer or until cheese melts.