Ingredients

1. 2 pounds parsnips, peeled and cut into 1-inch lengths
2. Kosher salt
3. 6 tablespoons unsalted butter, at room temperature
4. 1 cup all-purpose flour
5. Eight 6-ounce flaky white fish fillets with skin, such as red snapper, sea bass or cod
6. Freshly ground pepper
7. Balsamic-Glazed Red Onions, for serving

Directions

1. In a large saucepan, cover the parsnips with cold water. Add a large pinch of salt and bring to a boil. Simmer the parsnips over moderate heat until very tender, about 25 minutes. Drain the parsnips well, reserving 1/2 cup of their cooking liquid.
2. In a food processor, pulse the parsnips until coarsely chopped. Add the reserved cooking liquid and 2 tablespoons of the butter and season with salt; process until smooth. Return the parsnip puree to the saucepan and keep warm.
3. Put the flour in a shallow bowl. Season the fish fillets with salt and pepper, then dredge them in the flour; tap to remove any excess flour. Melt 2 tablespoons of butter in each of 2 large nonstick skillets. Add 4 fillets to each skillet, skin side down. Cook over moderately high heat, turning once, until golden brown and cooked through, about 8 minutes.
4. Spoon the parsnip puree onto warmed plates. Top with the fish fillets, skin side up, and serve with the Balsamic-Glazed Red Onions.

Make Ahead

The parsnip puree can be refrigerated overnight.