Cook the rice according to package directions, and set aside.
Dice the onion, shallot and garlic, and heat on medium in a very large frying pan, for 5 minutes.
Peel and dice the carrots. Dice the red bell pepper, squash, and cauliflower, and add to the onion mixture. Add the chili powder, cumin and black pepper, and stir well. Cook for 10 minutes, until veggies have softened.
Meanwhile, heat the garbanzo beans, and set aside.
Slice the mushrooms and the tomatoes, and add to the veggie mixture, cooking for a final 5 minutes.
Stir in the salt, and remove from heat.
Make the guacamole: scoop out the avocado, add the garlic (diced), the lime juice and the cilantro, and stir well.
In large bowls, layer the rice, veggies, garbanzo beans, and top with the guac. Serve immediately.