Step 1

Whisk yolk, water, and salt together in a large bowl.

Step 2

Drizzle in a few drops of oil while whisking.  Do this a few times until the yolk mixture starts to lighten in color.

Step 3

Continue adding oil, drizzling in a bit more each time while whisking.

Step 4

As the sauce firms up, you can drizzle in more oil each time.

Step 5

When the oil is all mixed in, the mayo should be very thick.  Serve with whatever you can put it on!