How to Make It
Cut 1 shallot into quarters. Stir together the quartered shallots, wine, water, lemon juice, caper liquid, pepper, fennel seeds, 4 of the thyme sprigs, and 2 tablespoons of the oil in a 3- to 4-quart slow cooker. Cover and cook on LOW until mixture is well incorporated, 2 hours.
Finely chop the leaves from the remaining 2 thyme sprigs. Thinly slice the remaining shallot. Stir together the chopped thyme, sliced shallots, cherry tomatoes, sliced fennel, capers, and remaining 2 tablespoons oil in a bowl. Stir 1 tablespoon of the wine mixture from the slow cooker into the relish.
Add the sea bass to the slow cooker, skin side up, and nestle into the wine mixture. Cover and cook on LOW until a thermometer inserted in the fillets registers 140°F and the fish flakes easily with a fork, 15 to 25 minutes. Transfer the fish to a platter, discarding the wine mixture in the slow cooker. Sprinkle the fish with the salt, and serve with the tomato-fennel relish.
Fennel is a cool-weather vegetable with a crunchy texture and a slightly sweet flavor similar to licorice or star anise. It’s composed of a bulb, stalks, feathery fronds, and seeds. This recipe makes use of two parts: fennel seeds to flavor the poaching liquid and sliced fennel bulb as the base for the relish.