In a bowl, combine the vegetable oil, lemon juice, minced garlic, ground cumin, garlic powder, onion powder, salt, and pepper. Add the chicken and coat it well with the marinade. Let it sit for at least 15 minutes to absorb the flavors.
Heat the olive oil in a large pot over medium heat. Once hot, add the marinated chicken to the pot. Cook for about 5-7 minutes on each side until golden brown and cooked through. Once fully cooked, remove the chicken from the pot and set aside.
In the same pot, add the chopped onion and bell peppers. Sauté for about 5 minutes until they are tender and fragrant. Add the additional minced garlic and cook for another minute.
Return the cooked chicken to the pot and pour in the chicken broth and milk. Stir well to combine everything.
Add the canned diced tomatoes (with their juices) and the penne pasta to the pot. Stir everything together, ensuring the pasta is submerged in the liquid.
Bring the mixture to a boil, then reduce the heat to a simmer. Cover the pot and let it cook for about 12-15 minutes, or until the pasta is al dente and has absorbed most of the liquid. Stir occasionally to prevent sticking.
Taste and adjust the seasoning with more salt and pepper if needed. Once the pasta is cooked and creamy, serve it hot, topped with your favorite salsa and a dollop of sour cream if desired.