Prepare the Filling: In a skillet over medium heat, add 1 tablespoon of vegetable oil. Sauté the onions until translucent. Add garlic and continue cooking until fragrant. Incorporate the shredded chicken, diced red bell pepper, grated carrots, chopped parsley, cumin and achiote powder. Stir well to combine. Pour in 1 cup of chicken broth, simmer for 10-15 minutes until the mixture is well-cooked and flavorful. Remove from heat and set aside.
Prepare the Dough: Place the corn flour in a large mixing bowl. Gradually add chicken broth, stirring continuously until a smooth, slightly stiff dough forms.
Assemble the Tamales: Take a soaked corn husk, spread a thin layer of masa (about 1-2 tablespoons) over the center, leaving space around the edges. Add a spoonful of the chicken filling down the center of the masa. Fold the sides of the corn husk toward the center, then fold the top and bottom to enclose the filling securely. Tie with a strip of soaked corn husk if desired. Repeat the process until all masa and filling are used.
Prepare the Instant Pot: Add 1 cup of water to the Instant Pot. Place a trivet or a steamer basket inside. Cook the Tamales: Arrange the tamales upright in the Instant Pot on the trivet. Close the lid and set the Instant Pot to Manual mode, high pressure, for 25 minutes. Allow natural pressure release for 10 minutes, then carefully release any remaining pressure.
Serve: Carefully open the Instant Pot and let the tamales cool slightly before serving. Serve with your favorite salsa or sauce.
Notes: Ensure that the dough has a spreadable consistency. If it's too thick, add a bit more chicken broth.