Prepare and knead the pizza dough. Place the ball of dough in a bowl, loosely covered, in a warm place to rise for one hour.
While the pizza dough is rising, make the hummus. Add enough liquid to the hummus so that it is easily spreadable with a spoon. Keep the hummus refrigerated until ready to use.
Wash the vegetables to remove debris. Slice the squash and onion into half inch thick pieces. Place the squash in a bowl and drizzle with 2 Tbsp of olive oil. Season with salt and pepper and toss to coat. Preheat a counter top grill and then grill the squash for about 5 minutes. Wipe excess oil out of the bowl the portabello cap and onion pieces. Grill them in the same manner as the squash. After the vegetables are grilled, cut into bite sized pieces. Also, cut one of the roasted red peppers from the jar into strips.
Once the dough has risen to about double its original size (about one hour), begin to preheat the oven to 450 degrees. Prepare a pizza pan with non-stick spray and a generous sprinkle of cornmeal.
Punch the dough down and, using floured hands, stretch it into a 16 inch circle. Using the back of a spoon, spread about half of the batch of hummus over top of the dough. Top with the grilled vegetables.
Bake the pizza for 20-25 minutes or until the outside edges of the crust are golden brown. Cut into 8 pieces and enjoy!