Pour vegetable broth in a large cooking pot. Let boil.
Add the onion, cook for a minute.
Put-in the broccoli, yellow squash, zucchini, green beans, and red bell pepper. Allow the liquid to re-boil and then cook for 5 to 7 minutes. Note: do not overcook the veggies. You can turn-off the heat if you think that they are already cooked.