Over medium-high heat (or medium sauté setting on your electric pressure cooker), brown chicken pieces in a couple tablespoons oil (you will probably need to do this in a couple batches.Remove chicken to a plateAdd onions to the pot (you may need to add a little more oil) and sauté until they start to softenAdd in the garlic and cook for a couple minutes longerStir in the oregano, cumin and chili powder and cook for about a minutePour just a splash of the chicken broth into the pot to deglaze, scraping up any bits that are on the bottomAdd the tomatillo salsaAdd the chicken stockTurn heat to high (if using an electric pressure cooker, switch from sauté to pressure cook mode)Place top on pressure cooker and bring to high pressureSet time to 8 minutesWhen time is up, remove from heat and do a quick releaseRemove topPut pot back on medium heat and stir in Masa-water mixtureLet simmer for about 5 minutesRemove from heat and serve with bread, tortilla chips or over riceTop with grated cheese, sour cream or yogurtI like to add a squeeze of lime to each bowl