Two authentic recipes for green chili are Chili Verde and Colorado Green Chili. Another good green chili recipe is Slow Cooker Hatch Green Chile Verde.
To make Colorado Green Chili, drizzle 1 tablespoon of vegetable oil over 3 Anaheim chiles, and roast the chiles at 400 degrees Fahrenheit for 20 minutes. Remove the stem and seeds from the chiles, and set them aside. Swirl 3 tablespoons of vegetable oil in a pot, and heat it at medium-high before adding 2 pounds of cubed boneless pork shoulder seasoned with salt and pepper to taste. Sprinkle 1 teaspoon of whole cumin seeds over the pork, and cook the meat for 15 minutes until brown. Remove the meat.
Add the chiles, 1 diced yellow onion, 1/2 cup of minced fresh cilantro and 6 minced garlic cloves to the pot, and saute them for 10 minutes. Whisk 1 tablespoon of all-purpose flour into the vegetables, and cook them for another three minutes before adding the pork back to the pot along with 1 16-ounce can of crushed tomatillos and 4 cups of chicken stock. After bringing the mixture to a boil, simmer it covered for 45 minutes and uncovered for 15 minutes. Serve the green chili with tortilla chips.