Mix the coriander, cumin, oregano, paprika, red pepper flakes, salt and pepper together in a small bowl.
Add olive oil to a pressure cooker set to saute and add the chicken. Sprinkle the spice mix over the chicken and toss. Cook until the chicken has started to sear on the outside, then add the broth.
Place the lid on the pressure cooker, set the valve to sealing, and cook on manual for 6 minutes. Release the steam using the quick-release cycle. Remove the chicken to a board and shred with two forks.
Put the heavy cream and masa harina in a small bowl and mix until smooth with a whisk or fork.
Switch the pressure cooker to saute and return the chicken to the pressure cooker along with the masa and heavy cream mixture, cannellini beans, green chiles and corn. Let cook, stirring occasionally, until the chili has thickened and the corn is warmed through, about 10 minutes.
Ladle the chili into 6 bowls. Top with cheese and avocado. Serve with lime wedges.