I've been watching too many cooking videos on YouTube lately. And simple pan sauces often finish most dishes. I am getting better at doing it.
For this cook, since I didn't have any pan drippings or fond as I cooked on the grill. So I sautéed some diced red onion in butter. Deglazed the pan with a glug of white wine. Added a couple of cups of chicken stock, and a tablespoon of chicken base. Reduce to concentrate flavor. Add a couple of nubs of butter to tighten it up a bit. At this point adjust seasoning.
This is a thin sauce and not a Hub approved gravy.