I mentioned this to a gardener at Sky Nursery and she passed this on to me... so I share. And this way, I can come look it up when I have the flowers.
(or how to look AMAZING at a buffet with just a Baguette, Salami & Butter)
1 stick unsalted butter - room temp or softened
5-8 Nasturtium flowers chiffonade
both chiffonade and chopped tiny
salt and lemon juice to taste
stir and whip all above together until well mixed
Roll into a cylinder in parchment paper or similar - refrigerate
Slice into thin rounds, spread on small slices of baguette, or simply place, and let them wilt in the heat.
The butter will look lovely, and yet be so tasty, it must be eaten. A thin slice of salami is a wonderful pair.