Place a medium Dutch oven or large pot over medium-high heat.
Pour the oil, and once it's ready, saute the garlic and onion until it softens.
Add the pieces of chicken and cook until they are no longer pink --- mix often and keep the pot uncovered.
Combine the crushed tomatoes and mix for a few minutes, coating the chicken.
Add the bouillon cubes, bay leaves, and one and a half cups of water.
Cover with a lid, turn the heat up to medium-high, and bring to a boil.
Lower the heat and simmer for about twenty minutes (with the lid on).
Add the carrots, potatoes, bell peppers, salt, ground black pepper, and one tablespoon of fish sauce.
Mix, place the cover back on, and continue simmering your chicken afritada until the vegetables soften.
Taste and adjust the seasoning by adding salt, pepper, or fish sauce.
Remove the pan from the heat, transfer to serving plates --- and enjoy!