1 egg
1/2 teaspoon lemon juice
1/4 teaspoon salt
1/4 teaspoon dry mustard
1/2 cup canola oil

1. Mix the egg yolk, lemon juice, salt, and dry mustard together in a large bowl. Whisk/blend to combine.
2. Pour in about a teaspoon of oil, whisk, and then pour in another teaspoon.
3. Keep pouring the oil in a slow drizzle, and whisking vigorously. Stop pouring in the oil once the mixture has emulsified into a smooth, creamy, thick sauce. You probably will not use all of the oil, unless the egg yolk is extra large.