Mayonnaise

1. Whisk egg yolk vigorously in medium bowl for 15 seconds. Add lemon juice, vinegar, mustard, and salt and whisk until yolk thickens and color brightens, about 30 seconds.
2. Add 1⁄4 cup oil in slow, steady stream, continuing to whisk vigorously until oil is incorporated completely and mixture thickens, about 1 minute. Add 1⁄4 cup oil, whisking until completely incorporated, about 30 seconds more. Add remaining 1⁄4 cup oil all at once and whisk until completely incorporated, about 30 seconds more. (Mayonnaise can be refrigerated for up to 3 days.)

LEMON MAYONNAISE
Add 1-1⁄2 teaspoons grated lemon zest along with lemon juice.

DIJON MAYONNAISE
Whisk 2 tablespoons more Dijon mustard into finished mayonnaise.

TARRAGON MAYONNAISE
Stir 1 tablespoon minced fresh tarragon into finished mayonnaise.

FOOD PROCESSOR MAYONNAISE

MAKES ABOUT 1-1⁄2 CUPS
Use 1 whole large egg and double quantities of the other ingredients in Mayonnaise. Pulse all ingredients except oil in food processor 3 or 4 times to combine. With food processor running, add oil through feed tube in thin, steady stream until completely incorporated.