In a small bowl, whisk together the vinegar, lemon juice, mustard, garlic, egg yolk, worcestershire sauce, salt, and pepper. While whisking, very, very slowly add the olive oil until emulsified. You can also do this in a food processor while slowly pouring in olive oil.
Taste and add salt if needed.
Notes
*As a disclaimer, there is a slight risk of salmonella when consuming raw eggs but this risk is drastically reduced/negligible when consuming fresh organic eggs. If you’re concerned about raw egg, simply omit it.