I think that this is the recipe REC: Brown Butter Brussels Sprouts
I googled the restaurant because I had a vague memory of having seen the recipe printed in an article about the chef, David LeFevre. I will mention that this restaurant has a wood burning oven, and I think that a significant amount of the flavor of this recipe in the restaurant is a result of that. I have had them in the restaurant (OMG good!!!), but never tried to replicate them at home ..if anyone tries, please report....?
Brown Butter Brussels Sprouts with Saba and Emmenthal
3 pounds Brussels sprouts, scored on the base and halved
½ pound Clarified Butter
½ cup toasted and halved Hazelnuts
48 leaves sage, chopped
2 cups grated emmenthal cheese
¼ cup Saba, (or aged balsamic vinegar)
Fluer de sel
White Pepper
Procedure:
Preheat Oven to 300 degrees, and place a baking dish or casserole dish in the oven.
In 3 batches:
Using a large sauté pan over medium heat, cook 1/3 of the clarified butter until it starts to smell nutty.
Add 1# of the Brussels sprouts making sure to have the cut side down touching the surface of the sauté pan. Cook the Brussels sprouts until they are dark brown and well caramelized on the cut surface. Next season them with fleur de sel and white pepper and then transfer to the baking dish in the pre heated oven. These Brussels sprouts will continue to cook while the others are being caramelized.
Repeat this process two more times until all Brussels sprouts are caramelized and in the oven roasting. Once the Brussels sprouts are just cooked through, sprinkle the hazelnuts, chopped sage, and Emmenthal cheese over the Brussels sprouts and drizzle the Saba on just before serving.
Note: make sure the brussel sprouts are cooked through before you add the other ingredients, the nuts and cheese will burn and/or congeal if reheated afterwards in the oven.