In a small jar, add the lemon juice, maple syrup, both mustards, garlic, anchovy (if using) and a generous grind of pepper.
Pour over the oil and secure the lid. Shake the jar vigorously until the dressing is thickened, homogenous and completely emulsified.
Video
Notes
Make Ahead
Store in a sealed jar in the fridge for up to 1 week. The olive oil will solidify when chilled - remove from the fridge 10-15 minutes before using and shake well to re-emulsify before dressing your salad.