French Onion Farro with Mushrooms and Green Beans

1. Preheat oven to 375°F

2. Caramelize your onions: Heat butter and olive oil in a large, deep sauté pan, ideally one that’s ovenproof, over medium heat. Add the onions, toss to coat them in butter and oil and cover the pot. Reduce the heat to medium-low and let the onions slowly steep for 15 to 20 minutes. You want to start the stirring process sooner if they’re browning or sticking to the pan. Uncover the pot, raise the heat to medium-high and stir in 2 teaspoons of kosher salt. Cook onions, stirring every few until the onions are brown, soft, and sweet, about 20 minutes more. You’ll want to reduce the heat to medium once any water the onions emitted has cooked off.

3. Assemble casserole: Add garlic to the onions and cook, stirring, one minute. Add sherry, if using, and cook until it disappears. Add the farro and cook for 2 minutes. Add lentils, mushrooms, green beans, broth and thyme and bring the mixture to a simmer. Season well with additional salt and black pepper. If your pan isn’t ovenproof, transfer it at this point to a casserole dish.

4. Bake the casserole: Cover the pan and bake, stirring after 20 minutes. Check to see if liquid is mostly absorbed and the lentils and farro are tender. If all of the liquid has absorbed, you may add an additional ¼ cup of water. Cover and bake an additional 10 minutes.

5. To finish: Uncover, sprinkle the dish with cheese and broil until browned on top.