Preheat oven to 450°.
Combine the first 7 ingredients in a large bowl, stirring with a whisk. Add cauliflower and bell pepper squares; toss gently to coat.
Spoon vegetables into a single layer on a jelly roll pan. Bake at 450° for 25 minutes or until lightly browned and crisp-tender, stirring after 15 minutes. Cool completely; stir in cilantro.
Thread 1 cauliflower floret and 1 bell pepper square onto each of 30 (6-inch) skewers.