In a large pot, heat the vegetable oil over medium heat.
Add the onion and red pepper and sauté until onions are translucent, about 3 minutes.
Then add the tomatoes, garlic, salt and ground pepper and sauté for 5 more minutes.
Add the chicken, water, chicken bouillon cube, sazón and cumin powder.
Cover and cook for 25 minutes, stirring occasionally.
Add the potatoes and cilantro and cook for an additional 30 minutes or until the potatoes are tender.
Serve over white rice.