Heat a large sauce pot over medium high heat. Add oil, bay leaf, onion, zucchini and yellow squash to the pot and season with salt and pepper. Saute, stirring frequently, 7 or 8 minutes. Add pumpkin and broth to the pan and stir to combine. Add cumin and coriander. Bring broth to a boil. Add couscous to the broth, stir, cover and remove from heat. Let stand 5 minutes. Remove lid from the pot and fluff couscous with a fork. Remove bay from the pan, add finely chopped tomato, cilantro and parsley, toss again with fork to combine and transfer to a serving platter. Serve with warm Mediterranean flat breads.