You can use leftover beans that you have cooked, as well as leftover chili. You can also use canned beans, drained, mixed with canned chili. This can be as easy or time consuming as you desire.
Make a V shaped cut into the poblano and remove seeds. Place in a 400° oven for 30 min.
In a mixing bowl, combine beans and chili to the desired ratio you like. You can also added diced onion and any other diced pepper that you like, I used fresno peppers. Add 1 c grated cheese as well if desired.
Stuff gently into poblano.
Top with grated cheese and bake 400° another 20min or until pepper is nice a soft. Top with cilantro, salsa, sour cream or any of your favorite toppings.