from Sundays at Moosewood Restaurant
2/3 cup plain yogurt
1 medium cucumber-peeled, seeded, coarsely chopped
2 Tbsp minced onion
1 Tbsp vegetable oil
2 tsp vinegar
¼ tsp salt (optional)
2 tsp chopped fresh dill (or fennel fronds) (optional)
Combine everything in a blender or food processor and puree until creamy and smooth. Chill. Will keep refrigerated for at least one week.