Storage: Store nasturtium blossoms and leaves in the refrigerator in their plastic clamshells. If they start to go limp, you may be able to refresh them by dipping them briefly in ice water right before serving.
Shelf Life: Up to ten days.
The most common usage for edible nasturtiums as a bright garnish or cake decoration. The blossoms can also be used as an ingredient (either whole or as petals) in salads, tea sandwiches, compound butters (how to make compound butter), or on finished omelettes. They can also be stuffed or filled with pre-cooked creamy salads like crab (crab salad recipe), lobster, chicken, egg, tuna, or small-diced potato.
Nasturtium leaves can also be tossed in salads, stuffed like grape leaves, or used (chopped) to top finished dishes (particularly soups or egg dishes) as you would microgreens.
Other flavors to pair nasturtium with include chives, cream cheese, chicken, seafood, mascarpone, blue cheese, cucumbers, mint, pears, nuts (especially almonds or walnuts), or apples.
Some edible flowers may wilt or change color when exposed to vinegar, so if using a vinegar-based dressing on salads containing edible flowers, test it on a few blossoms ahead of time and/or add it at the last second.
Edible Flower Recipes