Step 1

Arrange a rack in the middle of the oven and heat to 225°F.

Step 2

Spread the dulse out in a single layer on a baking sheet. Roast until dry and crisp, about 30 minutes. Remove from the oven and let cool for 10 minutes. Transfer to a food processor fitted with the blade attachment and process into fine, crumb-sized pieces, but not total dust.

Step 3

Add the butter and process until completely mixed in with the dulse, about 30 seconds, scraping down the sides of the bowl as needed.

Step 4

The dulse butter can be used immediately or placed in the refrigerator for a couple of hours to firm up a bit first. Enjoy it spread on slices of sourdough bread as an appetizer or snack.