For the chicken, in a heavy saucepan on medium heat, heat up oil. When oil is hot add the onions an cooked until translucent. Add the tomato paste, chiles, garlic and Adobo seasoning. Cook for about 1 minute while stirring.
Add the chicken and let the fat cook off the chicken. Cook on one side for about 5 minutes then turn and cook the other side for about 5 minutes. Add about 1 cup of water to the saucepan and cover. Cook for about another 10 minutes but keep an eye on it to be sure the chicken doesn't completely dry out. Taste the sauce to make sure it's well seasoned and adjust with more Adobo or water to taste.
While chicken is cooking, in another smaller saucepan, cook the onions in oil until translucent. Add the beans, tomato paste, oregano, Adobo, black pepper, cilantro and about 1/2 cup of water. Since beans are already cooked you just need to heat up enough so the flavors meld well together, about 5 minutes.
In a separate small pot, salt the water for the rice and cook as per the package instructions..
Once everything is done, preheat oven to 400 degrees. Mix the rice and beans in a bowl and add the cotija cheese. Stuff each of the jalapeno peppers with the mixture and add each individual, stuffed jalapeno to the bottom of the casserole dish.
Transfer the chicken to a cutting board and shred the chicken with a fork, then top the stuffed jalapenos. Drizzle any of the remaining juices from the chicken over the chicken and jalapenos.
As a final step, top the dish with the shredded cheese and bake for about 15 minutes and top of dish is crispy and cheese is melted.