Prepare the ingredients: Rinse 1 pound green beans under cold water to remove any dirt or residue. Trim off the ends.Wipe 8 ounces mushrooms clean with a damp paper towel. Use a sharp knife to slice them into your preferred thickness. Thicker mushrooms will produce a meatier bite. Make an ice bath for the green beans, fill a large bowl with ice cubes and cold water; set aside. Dice 3 tablespoons shallots
Bring a pot of water to a rolling boil. Carefully place the beans into the boiling water. Turn the heat off and let them sit in the water for about 3 minutes; they should be bright green. Carefully remove them from the water using tongs and place them into a bowl of ice water. Leave them in the ice water until they are completely cool; drain and pat dry.
Add olive oil to a large skillet and heat over medium-high heat. Once the skillet is hot, add the mushrooms and shallots. Reduce to medium heat; cook until the mushrooms start to turn soft.
Add the blanched green beans and toss. Adjust flavor with salt and pepper.
Notes
Store leftovers once cooled to room temperature in the refrigerator for up to 4 days. Reheat in the microwave or on top of the stove. Or enjoy them cold tossed in a salad or vinaigrette.Serve sauteed green beans with any entree such as chicken, beef, tofu, or seafood.