Makes 1 cup
This bright yellow sauce flecked with green and red is especially good with steamed cauliflower, broccoli, new potatoes, beets, celeriac, or fish. I like to use it as a dip for raw carrots, radishes, and fennel. It can also be used on sandwiches. Prepare the sauce at least 20 minutes before serving to give the flavors time to meld.
• 1 cup tightly packed flat-leaved parsley leaves
• 2 to 3 tablespoons fresh basil, tarragon, or fennel leaves
•1 large clove garlic
• 1 tablespoon capers
• 1/2 cup chopped red bell pepper
• 1 tablespoon Dijon or other prepared mustard
• 1/2 teaspoon salt
• 1 tablespoon plus 1 teaspoon herb or white wine vinegar
• 1/2 cup olive oil
1. In a food processor with a steel blade, pulse the herbs, garlic, capers, bell pepper, mustard, salt, and vinegar, stopping occasionally to scrape down the sides. With the motor running, add the oil through the feed tube and process to a rough puree.
2. Store, tightly covered, in the refrigerator as long as 5 days. Bring to cool room temperature before serving.
Click here for the original article, Herb to Know: The Mustard Seed.