I got the idea from a short video I came across on YouTube and tried to duplicate it.
-Soften 1 stick unsalted butter
-roast ~ 2lbs sliced marrow bones
-saute 3 chili peppers (I used green) until well blistered
-slice peppers, remove seeds, cut off stems, then dice
-add all of the above into a mixing bowl
-I zested about 1/3 of a lemon into the bowl
-Grate 1 Clove of garlic into bowl
-salt to taste
Incorporate well with a hand mixer then form into a log on parchment paper, wrap, and into the fridge.
Edit: here's the vid-
I've used it on pan seared scallops, steaks, pork chops, and fried an egg in it this morning for a breakfast sandwich.