Preparation

Briefly mix the orange juice, vinegars, salt, mustard and garlic with an immersion blender, food processor or blender, or with a fork or wire whisk. Slowly add the oil in stream (drop by drop if whisking) until an emulsion forms; or just whisk everything together briefly. Add the remaining oil faster, but still in a stream.
 
Taste to adjust salt and add more oil, vinegar or freshly ground black pepper if needed.

Makes 1-1/4 cup