There's really no way to mess this up. Make it more soupy (add more water) for wintertime, or more dry for the hot summer weather. There's no right or wrong amount of vegetables, and as long as the rice is cooked, the length of cooking time can vary greatly too, and will not affect the final outcome in a significant way; it's a very forgiving meal!
This is a perfect crock pot meal too. Just sauté the veggies, then transfer to the crock pot, adding the rest of the ingredients. Let cook all day. Easy-peasy!!