Green bean casserolecreamy mushrooms & crisp onions

• 1 1/2 lb fresh green beans, trimmed and cut
• 8 oz mushrooms, thinly sliced
• 1 medium onion, finely diced
• 3 garlic cloves, minced
• 2 tbsp olive oil, plus 1 tsp for greasing
• 1 cup plain Greek yogurt
• 3/4 tsp kosher salt for sauce, plus 1 tbsp for blanching water
• 1/2 tsp black pepper
• 1 cup crispy fried onions (about 2 oz)
• About 4 quarts blanching water, plus cold or ice water

Let's cook

• Heat oven to 375 F. Grease an 8 x 8 inch or 2-quart dish with 1 tsp oil. Bring the blanching water and 1 tbsp salt to a boil; set out a bowl of ice water.

• Trim beans and cut into 2 inch pieces. Boil 3 to 4 minutes, until bright green and tender-crisp. Drain, cool in ice water 1 minute, drain again and pat dry.

• Heat 2 tbsp oil over medium-high. Cook mushrooms and onion about 8 minutes, until moisture evaporates and edges brown. Add garlic for 1 minute; stir in sauce salt and pepper.

• Remove skillet from heat; cool 2 to 3 minutes. Stir in yogurt, then gently fold in beans. Taste; adjust salt if needed. Spread in the baking dish.

• Bake 10 minutes. Top with crispy onions; bake about 5 minutes more, until golden and bubbling. Watch the topping closely. Rest 5 minutes before serving.