Based on the sandwich from Butcher and Bee in Charleston.
Heat the oil in a medium saucepan over medium high heat.
Simmer on low heat for 15 minutes. (The next 2 steps are optional if you want a thinner sauce)
(optional) Remove sauce from pan and add to a small food processor.
(optional) Add 2 tbsp water and pulse. If sauce is still too thick add 1 tbsp water and pulse until sauce is more liquefied. Repeat with 1 tbsp of water at a time. Don't add too much water so you do not dilute the sauce. The sauce will still be slightly thick, even with 3-4 tbsp water.
Pulled Squash Sandwiches Southern Style Mustard BBQ Sauce https://beautyandthebeets.com/bbq-pulled-squash/