Preheat the oven to 475°F. Once the oven has come to temperature, place Holy Sheet in the oven to preheat as well.
In a large mixing bowl, combine the Brussels sprouts, ¼ cup of olive oil, 1 teaspoon of salt, ½ teaspoon black pepper, and ½ teaspoon of honey. Toss well to combine, then spread them out on the preheated Holy Sheet. Roast for 15-25 minutes, depending on the size of your Brussels sprouts. Smaller Brussels sprouts cook in a jiff, so be on high alert to not let them over cook. The beauty of a very hot oven paired with a preheated sheet tray is that you’ll be able to quickly achieve a deep caramelization of the vegetable, which is perfect when working with a smaller vegetable that otherwise risks over cooking. If using particularly large Brussels sprouts, you can lower the oven temperature to 450°F once the outer leaves have sufficiently browned to prevent the Brussels sprouts from burning before cooking all the way through. When the Brussels sprouts have taken on a deep, caramelized char and are just cooked through, remove them from the oven.
While the Brussels sprouts are roasting, prepare the other components of the dish. In a medium mixing bowl, add the thinly sliced shallots, vinegar, and a pinch of salt. Set aside to quickly pickle for a minimum of 5 minutes. Add the mustard, honey, red pepper flakes, and a pinch of honey to the bowl. Stir to combine, then add the diced apples plus 3 tablespoons of olive oil. Mix to incorporate.
Combine the apple and shallot mixture with the roasted Brussels sprouts. Transfer to a large serving plate, scatter over the chopped hazelnuts, and nestle in the shards of cheddar cheese. The objective is to make sure there’s enough nuts and cheese for every bite, so don’t skimp!