Put everything into a jar and blend with an immersion blender, or shake vigorously. You can also use a food processor or a blender to get a good emulsion, too, but an immersion blender is the easiest. Taste to adjust any of the ingredients.
Store covered in the refrigerator for up to 2 weeks.
Notes
Use this same formula with other citrus like pink grapefruit, lime, orange, or blood orange.
Add 1/4 cup of buttermilk or sour cream to this recipe for a creamy lemon poppy seed dressing.