Using the proportions given here, it's easy to scale this recipe up or down. This will make about 1 3/4 cups.
3 T. tarragon vinegar
3 T. lemon juice
1 - 2 t. Dijon mustard
1 clove garlic, halved (see note)
1/4 t. salt
1/8 t. freshly ground black pepper
1 1/4 cups light olive oil or other vegetable oil
1 - 2 T. of chopped basil, oregano, thyme OR tarragon
In a small bowl or jar, mix the vinegar, lemon juice, mustard, garlic, salt and pepper together.
Add the oil and mix all ingredients until well blended and smooth. Add the chopped herbs. Blend well again just before using.
Garlic Note: Because garlic can overpower a salad, add a halved garlic clove instead of chopped garlic to the dressing. In this way you can remove it when the dressing has acquired sufficient garlic flavor.
From French Classics Made Easy by Richard Grausman.