Add: 1 grated garlic clove or 1 teaspoon horseradish (for beets for example) or 1 tablespoon ketchup/ mayonnaise/ chili sauce.

Add: other herbs, like chives, coriander, dill, etc.

Add: 1 or 2 very finely chopped anchovy fillets.

Add: 1 or 2 very finely chopped gherkins.

Replace: olive oil with other kinds of oil (you could even leave it out completely)

Replace: white wine vinegar with balsamic vinegar or red wine vinegar or any other sorts of vinegar.

Replace: regular mustard with Dijon mustard, grainy, or sweet mustard.

Replace: maple syrup or honey, agave syrup or 1 teaspoon sugar, or leave out completely if you are already using ketchup, chili sauce, or sweet mustard.

I almost always use low-fat creamy yogurt, but you can take the full-fat version or Greek yogurt. Sour cream, smetana, or creme fraiche taste great as well, but they all have a lot more calories.

Chop the onion very finely.

Place the yogurt in a small bowl, add the mustard and stir well together. Add the vinegar, salt and pepper, and the olive oil. Whisk until the mixture emulsifies a little bit. Stir in the onion and the herbs.

This will make enough to dress a large salad, you could double the quantities and keep the rest in the fridge. It will keep for 2 or 3 days.