It’s not the end of your dish if you discover you’re out of prepared mustard. Prepared mustard is a combination of powdered mustard seed and a liquid, such as water. Creating your own prepared mustard is simple, as long as you have some form of mustard seed in your cupboard. You can also substitute horseradish for mustard if you need.
Grind mustard seeds with a mortar and pestle to make homemade mustard. The seeds should be ground enough that they make some powder, although they don’t have to be ground so finely if you want flecks of extra fire in your mustard. Mix the seeds with mayonnaise for a creamy mustard. Combine the seeds with oil and vinegar for a tangy mustard or mix them with water and honey for a sweet option. The ratio of seeds to liquid all depends on how thick you want the mustard.
Prepared horseradish is a mixture of ground horseradish root and liquid, such as vinegar. Like mustard seeds, horseradish adds bite to any dish. You can blend the minced root with water, vinegar, oil, mayonnaise or honey to produce different flavors of prepared horseradish. However, freshly prepared horseradish tends to be slightly stronger in flavor than prepared mustard, so it’s best to use less horseradish than the amount of prepared mustard called for in the recipe.