Warm olive oil in a heavy 4-quart saucepan over medium heat. Add onions and sauté several minutes until translucent. Add a pinch of salt, peppers, carrots, and cherry tomatoes; sauté 8 minutes more. Stir in garlic, oregano, and cilantro stems. Add the hominy and cooking liquid, bring to a boil, cover, lower heat, and simmer 15 minutes.