Haddock With Warm Frisee and Mushroom Salad

"Real Simple" magazine.

• Ready In: 40 mins
• Serves: 4

Ingredients

• 5  tablespoons olive oil
• 3⁄4 lb  mixed mushrooms, trimmed and cut into bite-sized pieces (such as button, cremini, shiitake)
•  kosher salt
•  fresh ground black pepper
• 1⁄4 cup cider vinegar
• 2  teaspoons Dijon mustard
• 1  pinch sugar
• 1  head frisee, leaves torn (4 cups)
• 1⁄2 head radicchio, leaves torn (2 cups)
• 24  ounces haddock fillets (sub cod or bass)

Directions

1. In a large skilet over medium high heat, heat 2 tablespoons oil, add the mushrooms, and season with salt and pepper; cook, tossing frequently, until tender and golden, about 10 minutes.
2. Transfer mushrooms to a plate with a slotted spoon, and remove skillet from heat.
3. Add vinegar and scrape up any browned bits from the bottom of the skillet; whisk in mustard, sugar, salt and pepper, 2 tablespoons of oil, then stir in lettuces and mushrooms.
4. Meanwhile, season fish with salt and pepper; heat another skillet over medium high heat.
5. Add oil and cook fish until opaque, about 3 to 4 minutes per side; serve with the salad.