Combine the cumin, chili powder, oregano, salt and pepper in a bowl. Sprinkle the seasons over the chicken breasts on both sides.

Heat the instant pot on the sauté setting. Add a quick swish of oil and sear the chicken breasts on both sides for a minute on each side. Do this in batches so the chicken sears rather than steaming. Remove the chicken to a plate. Add the onions and pressed garlic, let cook 2 minutes flipping as needed to brown all sides evenly.

Add the chicken back into the pressure cooker along with the orange zest, orange juice, lime juice, chicken broth, whole chipotle pepper(s), adobo sauce, bay leaf, and cilantro. Cover the instant pot and  let pressure cook on the 'chicken' setting for 8-10 minutes depending on the size of the chicken breast. Prepare the chipotle sauce while you wait for the chicken to cook. Allow the pressure to release naturally or turn to the 'vent' setting. Allow it to vent completely before removing the lid.

Position a rack in the center of the oven and preheat the oven to the 'broiler' setting. Remove the chicken breast to a clean surface and shred the chicken using 2 forks. Place in a large bowl and drizzle ¼ cup of  cooking liquid over the shredded chicken and toss to coat. Drizzle 1 tablespoon of the oil over the surface of a baking sheet. Add the chicken and drizzle the second tablespoon of oil on top. Stir to coat evenly.

Broil the chicken for 10-12 minutes stopping half way to toss the chicken and drizzle another 1-2 tablespoons of cooking liquid. Rotate the pan for even broiling.

While the chicken is pressure cooking, add the sauce ingredients to a blender and blend until smooth.