This is excellent on fish.
You may never use tartar sauce again. :)
Lemon Herb Sauce
3/4 cup mayo, light mayo, white salad dressing (looks just like mayo and often next to the mayo on the grocery store shelves), or plain yogurt
1 Tbsp. lemon juice
1 Tbsp. Horseradish *optional
2 1/2 tsp. fresh thyme OR 1 tsp dried thyme
Salt and Pepper to taste.
Combine the ingredients in a small bowl. Blend well.
Cover and chill until ready to serve.