In a small saucepan, combine butter, vinegar, mustard, honey, and salt. Bring to a simmer, and whisk until combined and honey has dissolved. Allow to cool slightly.
In a large bowl, toss the sprouts and glaze together until coated.
Spray a baking sheet with oil, then add the Brussels sprouts and place in oven.
Roast sprouts on bottom rack until softened, tender, and browned, 20–25 minutes.
To serve, top sprouts with nuts, blue cheese, and pomegranate seeds.