SERVES 1

Ranch dressing was originally sold by its inventor, Steve Henson, as a seasoning packet that contained, among other ingredients, dehydrated garlic, dehydrated onion, black pepper, and dried parsley; all cooks had to do was add mayonnaise and buttermilk. Our version uses fresh herbs, but fresh garlic and onion won't do: only the dried powders produce this dressing's characteristic flavor.

1⁄2 cup buttermilk
1⁄2 cup sour cream
1⁄2 cup mayonnaise
1 tbsp. finely chopped fresh chives
1 tbsp. finely chopped fresh flat-leaf parsley
1 tsp. garlic powder
1⁄2 tsp. onion powder
Salt and freshly ground black pepper
2 lightly packed cups watercress, washed and trimmed
3 cherry tomatoes
Few thin cucumber slices  

1. Put buttermilk, sour cream, mayonnaise, chives, parsley, garlic powder, onion powder, and salt and pepper to taste into a bowl; stir well.

2. Arrange watercress, tomatoes, and cucumber slices on a salad plate. Drizzle some of the dressing over the top. (Reserve remaining dressing for another use.)