Source: The Martha Stewart Show, September 2009
- 2/3 cup olive oil
- 1/3 cup extra-virgin olive oil
- 1 sprig fresh rosemary
- 3 cloves garlic
- Coarse salt
- 2 large egg yolks
- 1 teaspoon freshly squeezed lemon juice
Place both oils in a small saucepan with rosemary. Bring to a simmer over medium heat. Immediately remove from heat and let stand overnight; strain, discarding solids.
Coarsely chop garlic, and gather into a pile; sprinkle with a pinch of salt. Place flat side of knife blade on top of garlic, with sharp side of blade away from you; press down firmly while pulling knife toward you to create a paste; set aside.
In a medium nonreactive bowl, whisk egg yolk until light in color. Whisk in garlic paste and whisk in infused oil in a slow, steady stream until emulsified. As the sauce thickens, add 1 teaspoon water, 1/4 teaspoon at a time, to thin out. Whisk in lemon juice; season with 1/4 teaspoon salt. Keep refrigerated until ready to use.