1 large pinch sea salt
1 teaspoon Dijon mustard
1 tablespoon red or white wine vinegar, or freshly squeezed lemon juice
1 large egg yolk
1 cup (250ml) peanut oil
1/4 cup (60ml) fine quality, extra-virgin olive oil (or other oil)
1. Place a wet towel under a medium-sized, non-reactive bowl to keep it from sliding around. Then, place the salt, the mustard, and the vinegar in the bowl and whisk them together. Whisk in the egg yolk, then VERY SLOWLY, in a fine stream, whisk in the oils. The mixture will thicken as you whisk. You may stop adding oil when it gets to the thickness you desire.
About 1-1/4 cups (310ml)