Prepare green beans: Add green beans to a microwave-safe bowl. Fill with a little water. Cover bowl with plastic wrap or a plate. Cook for 4-5 minutes, until soft. Uncover, drain water. Set aside.
To make in an instant pot: Coat instant pot with cooking spray. Set to sauté. Add olive oil and heat. Stir in onions, potatoes, and garlic. Cook for 3 minutes. Stir often. Be sure to use a rubber spatula to sauté so potatoes won’t break. Stir in tomatoes, enchilada sauce, chicken, and seasonings. Mix well with a rubber spatula. Set on Poultry setting. Cook 16 minutes. Open vent. Let sit for 2 minutes before removing the lid. Open the instant pot and stir in steamed green beans.
To make on the cooktop: Coat a large pan with cooking spray. Add olive oil and heat. Stir in onions, potatoes, and garlic. Cook for about 8-10 minutes, to soften. Stir often. Be sure to use a rubber spatula to sauté so potatoes won’t break. Stir in tomatoes, enchilada sauce, chicken, and seasonings. Mix well with rubber spatula. Bring heat to a boil, turn down to simmer, cover, and cook for 25-30 minutes until chicken is cooked through and potatoes are soft. Stir in steamed green beans.
To serve: Line each bowl with 1 cup shredded lettuce. Add about 1½ cups of enchilada mixture to each bowl. Serve or top each with 2 tablespoons cheese and with 1 tablespoon sour cream or yogurt, if desired. Repeat with each serving.
Any leftover chicken enchilada mixture freezes great. Can use this filling to create tacos or burritos.