The instructions for the basting sauce I tried to make called for heating olive oil, butter, Dijon mustard, vinegar, and pepper and then whisking together until smooth.
I heated the oil, added the butter to melt, and then added the mustard. I skipped the vinegar.
When I added the mustard, it turned into tiny clumps and no amount of whisking would get it incorporated. What did I do wrong?
I don't think it was leaving out the vinegar; could it have been that?