Grind mustard seed with mortor and pestle or spice grinder. Place in bowl and stir in mustard powder, salt, wasabi and turmeric. Stir in jelly and vinegar to make paste. Cover bowl and let stand 3 hours. Stir with mayonnaise. Spoon into dry, sterilized jars. Seal tightly and store in fridge for 6 weeks.
**Wasabi powder is from Japan, it is a variety of green horseradish it is found in most grocery stores or specialty stores.