Add vegetable oil to a large pot over medium-high heat. Add onions, tomatoes, red pepper, yellow pepper, salt and pepper. Cook for 6 minutes, stirring often.
Add tomato paste and taco seasoning. Cook an additional minute, stirring often.
Add chicken, pinto beans, rice and water. Season with salt and pepper. Bring to a boil over high heat.
Once boiling, cover and reduce heat to medium low. Simmer for 20 minutes. Remove from heat.
Stir in cheddar cheese and cilantro and serve hot.