Roasted Brussels sprouts sandwich with bacon & pickled onions

A drunken evening at Searsucker Restaurant which included some mighty-fine Brussels sprouts resulted in the following:

Roasted Brussels Sprouts Sandwich with Bacon and Pickled Onions
Serves 2

½ Red onion, thinly sliced
¼ c. Cider vinegar
1-2 Bay leaves
1 sprig Thyme
½ t. Salt
5-6 peppercorns
½ c. boiling water
½ – 1 lb. Brussels sprouts, trimmed and cut in half
3 T. Walnut oil
1 clove Garlic, finely chopped
2 T. Mayonnaise
2 T. Pomegranate molasses
4 strips Applewood smoked bacon, cooked crisp
½ c. Gruyere cheese, grated
2 Kaiser rolls, toasted

Preheat oven to 375. Combine onion, vinegar, bay, thyme, salt and peppercorns in a small bowl. Cover with boiling water and slightly stir. Set aside (I weigh mine down with a saucer to ensure the onions are submerged). Combine brussels sprouts, walnut oil and salt and pepper in a roasting pan and place in the oven. Roast for approximately 45 minutes until beginning to brown, stirring occasionally (I cook my bacon on a separate rack in the oven at the same time, about 35 minutes). While brussels sprouts cook, make aioli by combining garlic and mayonnaise and set aside. After 45 minutes, drizzle sprouts with pomegranate molasses and return to the oven for 10 minutes longer or until molasses thickens and coats the sprouts.

Spread aioli on rolls. Layer with drained pickled red onion and bacon. Pile Brussels sprouts on bacon and cover with Gruyere cheese. Drizzle a small amount of Pomegranate Molasses over melting cheese.