Pre-heat the oven to 350°. Slice a head of garlic in half and place on a sheet of aluminum foil. Drizzle 1 tsp of extra virgin olive oil on the garlic and season with salt and pepper. Wrap in the foil and place in the oven for about 45 minutes. The garlic is done when the cloves are soft, brown, almost pulpy and can easily be squeezed from the paper.

Combine garlic, lemon juice, and mustard in a small food processor or blender and purée until smooth. With the motor running, slowly stream in the oil until emulsified. Taste and adjust seasonings with salt and pepper.