Step 1

Place egg yolks in a food processor. (To avoid using raw eggs, substitute yolks from pasteurized eggs.)

Step 2

Add mustard, anchovies, Parmesan, and lemon juice. Pulse ingredients until well combined.

Step 3

With motor running, add oil in a slow, steady stream (mixture should become thick and emulsified). Season with salt and pepper.

Step 4

Refrigerate in an airtight container, up to 1 week.