You can easily pick up a bottle of mustard powder from the store, or, if you're feeling extra crafty in the kitchen, you can also make your own by grinding mustard seeds in a spice or coffee grinder.

Garden cress is in season from July to March, and mustard seeds ... for up to one week. Add mustard cress to salads, sandwiches, vegetable purées, or Japanese-style soups. To prepare, pick ...