Variation: In place of cumin, add ½ to 1 teaspoon of dried basil or 1–2 tablespoons fresh basil.
Place the vinegar, lemon juice, garlic, mustard, honey, sea salt, and pepper in a blender and blend.
Add the fresh chopped parsley and onion. Blend.
Add oil and blend (if possible, slowly stream in olive oil through an opening in the top of the blender).
Serve at room temperature.