Lightly coat a grill pan with high heat oil then warm over medium-high heat. Arrange the onion rounds, zucchini, bell peppers, mushrooms, corn, and limes on top. Cook for about 5 minutes on each side, until softened with golden brown grill marks. Alternatively, you can spray the vegetables with oil then arrange on a gas grill and cook accordingly.Divide the cooked rice among the bowls and top with chopped cilantro. Chop any large pieces of vegetables into bite size piece then place on top of the rice. Sprinkle everything with salt & pepper then top with a large scoop of hummus and a squeeze of grilled lime juice. Serve warm with pita and enjoy!