Unlike most sauces, which should be applied toward the end of grilling, this one, from Gourmet Magazine, should be used to coat the food beforehand.  It is excellent with meat, poultry, or shellfish.

Ingredients:

1 tablespoon oil
2 teaspoons paprika
1/2 teaspoon ground cumin
1/4 teaspoon ground cardamom
1/4 teaspoon ground ginger
1/8 teaspoon cayenne
1/4 cup plain yogurt
2 tablespoons fresh lemon juice
1 large garlic clove, chopped and mashed with 1/2 teaspoon salt

Directions:

Cook oil, paprika, cumin, cardamom, ginger, and cayenne over moderate heat until mixture sizzles.  Cook one minute.  In a bowl stir together remaining ingredients and stir in spice mixture until combined.