Buttermilk Poblano Gravy

I made this for Thanksgiving at the Morgan's this year. It pairs nicely with Keith's smoked turkey that we have had for the past few years. I found it in the November 2019 issue of Food & Wine.

2 large poblano chilies
3 T unsalted butter, divided
1/2 cup diced yellow onion
1 1/2 cups vegetable or chicken stock
1 T flour
2 T whole buttermilk
Salt and Pepper

1. Roast poblano peppers under broiler on all sides until blackened. Place in a bowl, cover with plastic wrap and steam for 10 minutes.

2. Rub off skin from chiles using plastic wrap covered hands. Remove and discard stems and seed. Finely dice 1 chile. Cut remaining chile into strips and set aside.

3. Melt butter in a medium skillet over medium high. Add onion and chile strips. Cooks until soft. Combine onion mixture and 1/2 cup warm stock in a blender, and process until smooth.

4. Melt remaining butter in same skillet over medium. Whisk in flour and reduce heat to low. Cook, whisking constantly, until mixture is golden brown, about 3 minutes. Add onion and chile puree and remaining 1 cup warm stock. Cook whisking constantly until thick enough to coat the back of a spoon, about 2 minutes. Reduce heat to low, add buttermilk and diced chile. Simmer gently to allow flavors to meld. Season with salt and pepper.