Prep: Prepare all the vegetables by chopping the onions, poblanos, red, and yellow peppers, tomatoes, celery, carrot, and garlic.
Assemble & cook: In a large pot, heat up the olive oil and then add in the celery, carrots, red and yellow peppers, onions, and poblano peppers. Cook the mixture for about 10 minutes on medium heat, stirring occasionally, until the carrots are slightly softened.
Now add in the garlic to the vegetable mixture and cook for another minute or two until you can smell the garlic fragrance in the air.
Then add all the seasonings, except the cornstarch, to the sauteed vegetables. Stir well and cook for another 5 minutes over medium-low heat.
Add in the cornstarch and stir again until it's well combined. Pour in the vegetable broth, chia seeds, garbanzo beans, brown rice, tomatoes, corn, tomato paste, and vinegar to the pot. Give it a few good stirs to ensure all the ingredients are well combined.
Simmer: Continue to cook on medium-high heat until the mixture is brought to a boil, stir and then reduce the heat to low, let the soup simmer for 45 minutes. After 45 minutes stir the soup again and let cook for 15 more minutes.
Lastly add in the lime juice, soy sauce, and spinach and stir. Turn the stove back up to medium heat and let the spinach cook and wilt for 10 minutes. Serve the soup immediately and enjoy!