1. Bring the salt and water to a boil in a small saucepan.
2. Put the nasturtium seedpods in a half-pint glass jar and pour the boiling brine over them.
3. Cover and let them soak at room temperature for 3 days.
4. Drain the nasturtium seedpods in a fine sieve and return them to the jar.
5. Bring the vinegar, sugar, bay leaves, and thyme to a boil in a small (1-quart) saucepan.
6. Pour the boiling vinegar mixture over the seedpods and let cool.
7. Cover the jar and refrigerate for 3 days before using. They'll keep for 6 months in the refrigerator if covered in the vinegar.
Adapted from The Herbfarm Cookbook by Jerry Traunfeld (Scribner 2000). Copyright 2000 by Jerry Traunfeld.
"Often you find that there are ways you can improve techniques or recipes," says J. Kenji López-Alt, author of The Food Lab: Better Home Cooking Through Science.