This is a lovely, spicy, warm flavored sauce that can be adapted by adding other ingredients. I often stir in hard-boiled eggs or bread crumbs soaked in vinegar, which adds different textures.
Serve with fish, cooked meats, cheese and salads.
Put the mustard leaves and garlic into a food processor and blend with 2 tsp vinegar. With the processor still running, add the olive oil in a slow stream, season to taste, then add the remaining vinegar if required.
Reprinted with permission from Jekka's Herb Cookbook by Jekka McVicar, Firefly Books 2012.
"It's a whole lot easier to make your kitchen work for you than against you," says Brian Wansink, the John S. Dyson Professor of Marketing and director of the Cornell University Food and Brand Lab. "You're going to reduce how much other stuff you eat, but you're going to be doing it unconsciously." He is the author of Slim by Design.