Arctic Char with Chinese Broccoli and Sweet Potato Purée

Measure 3 cups puree and transfer to microwave-safe bowl.

Stir in mustard.

Season with salt.

DO AHEAD: Can be made 1 day ahead.

Cover and chill.

Boil vinegar in small saucepan until reduced to ` cup, about 8 minutes.

Stir in soy sauce.

Remove from heat.

Cook broccoli in pot of boiling salted water until crisp-tender, about 1 minute.

Drain; set aside.

Cook bacon in medium skillet over medium heat until edges are crisp.

Transfer to paper towels to drain.

DO AHEAD: Reduction and broccoli can be made 2 hours ahead.

Let stand at room temperature.

Process mustard seeds in spice grinder until coarsely ground.

Sprinkle fish with salt and pepper.

Sprinkle ground seeds over top of fish.

Heat 1 tablespoon oil in large skillet over medium-high heat.

Add fish, mustard side down, and cook until brown and just opaque in center, about 3 minutes per side.

Meanwhile, rewarm puree in microwave until heated through.

Heat 1 tablespoon oil in another large skillet.

Add broccoli and bacon; sauté until heated through.

Season with salt and pepper.

Divide broccoli, fish, and puree among plates.

Drizzle with balsamic reduction and serve.

*Chinese broccoli is also called gai lan or Chinese kale; it's available at Asian markets.

Broccoli rabe is an Italian leafy green vegetable with scattered clusters of broccoli-like florets; you'll find it at some supermarkets and at specialty foods stores.