Preheat oven to 400F.
Cut 2 poblanos in half lengthwise and remove the seeds. Place on a sheet pan and bake ~20 mins, until browning and fork tender, turning halfway through cook time. Set aside to cool.
Chop 1/2 bunch green onions.
Dice 1 ½ pounds chicken breasts. Heat 1 Tbsp olive oil in a large saute pan over medium heat. Add diced chicken + 2 tsp taco seasoning and cook 3-4 minutes. Set aside.
Dice roasted poblanos and add to cooked chicken.
Lower oven to 350F. Grease an 8x11 casserole pan.
In a medium bowl combine 8oz sour cream and 8oz salsa verde.
In the casserole dish layer ½ of the chicken/chile mix on the bottom topped w/ half the sour cream/salsa & 1/2 shredded cheese.
Repeat layers again.
Bake in oven ~20 mins until cheese is melted and chicken is warmed through. Top w/ chopped green onions.