Step 1

Preheat the oven to 300° F.

Step 2

Separate the cloves from the head(s) of garlic, peel the cloves, and place them in a single layer in a small, shallow, ovenproof baking dish.

Step 3

Add just enough olive oil to cover the cloves, then place in the oven and cook 45 minutes to an hour, until the cloves are very soft.

Step 4

Cool the garlic and oil, then transfer into a covered container or glass jar. Store in the refrigerator for up to one week.

Step 5

Cook the potato in a good amount of salted water until tender. Drain, let the cooked potato dry out briefly, then add to a mixing bowl and mash or rice the potato. Crack the eggs into a bowl, add a pinch of salt, and lightly beat them. Stir the beaten eggs into the potato until well incorporated, then set aside.

Step 6

Place the cod in a pot, adding the bay or thyme and enough milk just to cover it. Bring to a simmer and cook over medium heat until the cod flakes easily with a fork. Remove it from the milk and set aside.

Step 7

Add about 1/2 cup of the warm milk to the potato mixture, stirring well. Mash some of the garlic confit to a paste (8-12 cloves, or to taste), and add it to the potato mixture along with 2-3 tablespoons of the garlic-infused oil and the lemon zest, beating the mixture well until it is fairly smooth.

Step 8

When the cod is cool enough to handle, break it up with your fingers into very small pieces and add to the potato mixture, stirring well to incorporate. Taste to adjust seasoning, adding additional garlic or salt if desired.

Step 9

Pinch off small amounts of the mixture and roll into balls about the size of a golf ball (the mixture will be pretty sticky). Spread the breadcrumbs on a plate or platter and roll the croquettes in the crumbs to coat. Heat the oil until it shimmers, then fry the croquettes a few at a time until golden brown. Drain the croquettes on paper towels, sprinkling them with flaky salt as they come out of the hot oil.