Jeff Layman wrote:
Nasturtiums flower petals can be eaten in salads. I've seen it used
in very fancy restaurants and they have a peppery taste.

I was sometimes given nasturtium leaf sandwiches to eat by my mother
when young. They were quite as peppery as the flowers and nice.

Always worth checking the back of the leaves first for cabbage white
butterfly eggs or blackfly.

Hmm, hadn't noticed those, but I did notice that when my kids were munching
through nasturtium flowers summer before last a lot of them had little tiny
black beetle things hiding down inside the deepest bit of flower!