Season the chicken thighs and drumsticks with salt, black pepper, and aliño. Let them marinate in the fridge for at least 4 hours, up to 24 hours.
Heat achote oil in a large Dutch oven over medium heat.
Add minced garlic and cook for about 1½ minutes or until fragrant.
Add the diced medium red onion and cook for another 1½ minutes.
Add diced green bell pepper and cook for 1½ to 2 minutes until softened and aromatic.
Place the marinated chicken on top of the sautéed vegetables.
Rinse the marinade bowl with 1½ cups water, swirling to collect all seasonings, then pour into the pot.
Cover and cook the chicken on medium heat for 20–25 minutes.
Turn the chicken pieces over, add the peeled and medium-sized potato chunks, and add the peas and carrot mix. Cook uncovered for 5–10 minutes.
Blend the tomato, cilantro, and ½ cup water until smooth.
Pour the blended tomato and cilantro mixture into the pot and stir to combine. Cover, leaving the lid slightly ajar, and simmer for 5 minutes.
Turn off the heat and let the stew rest a few minutes.
Serve hot over steamed rice alongside fried ripe plantains.