Step 1

In a medium bowl, muddle the garlic and the lemon zest together with the sea salt.

Step 2

Rinse the fish, then cut them into 1/2-inch pieces. (If they're too big, you'll end up with lovely pickled fish, but not much sauce.)

Step 3

Toss the fish pieces (including the heads and tails) in the muddled salt mixture to completely coat the fish. Add in the peppercorns and bay leaves, then lightly pack the mixture into a clean 1-quart mason jar, pressing down on the pieces as you go to release the juices.

Step 4

Pour the sauerkraut brine or additional salt into the jar, then pour in as much water as needed to completely submerge the fish, but be sure to leave at least 1-inch of headspace at the top of the jar, as the mixture will expand as it ferments.

Step 5

Cover tightly and leave at room temperature for 2-3 days, then move to the refrigerator and let sit for 4-6 weeks.

Step 6

Double strain the mixture through a fine sieve or cheesecloth and discard the solids. Store in glass bottles in the refrigerator for 4-6 months.