Makes 2 cups
3 large egg yolks
1½ tsp Dijon mustard
2 cups grapeseed or canola oil
1 Tbsp ice water
2 tsp fresh lemon juice
½ tsp kosher or sea salt
Small pinch of cayenne pepper
Freshly ground black pepper to taste
Whisk the egg yolks and mustard together in a small deep bowl until the yolks have thickened and lightened slightly. Whisking constantly, begin to add the oil drop by drop, to allow the yolks to absorb the oil, until an emulsion has formed. Once the mixture begins to thicken, you can add the oil a little faster, but be careful – if you add it to fast it might separate. When half the oil has been added, drizzle in the ice water and 1 teaspoon of the lemon juice to stabilize the emulsion.
Continue adding the remaining oil in a steady stream. The mayonnaise should be thick and glossy. Add the remaining 1 teaspoon lemon juice along with the salt, cayenne and black pepper.
Transfer to a bowl or other container, cover tightly and refrigerate until ready to use. The mayonnaise will keep refrigerated for up to 3 days: check the seasoning before serving and add more salt, if needed.