Roasted Brussels Sprouts with Dijon and Crispy Topping

I'm always looking for ways to prepare brussel sprouts without using lots of fatty ingredients - mainly heavy cream, as so many brussel sprout recipes do.  While this appears to use quite a bit of oil, most is used to roast the sprouts, so not as much actually ends up in the dish as would appear.  I added the balsalmic reduction before topping with the crumbs to give it a little extra flavor- I try to always keep a reduction in the fridge to spruce up recipes that need a little something, something.

Roasted Brussels Sprouts with Dijon and Crispy Topping

1/8 cup plus 1/2 Tbs. extra-virgin olive oil
1 Tbs. Dijon mustard
1/2 tsp. Worcestershire sauce (Lea & Perrins is GF)
1/4 tsp. kosher salt; more to taste
Freshly ground black pepper
1 lb. Brussels sprouts, ends trimmed, cut through the core into quarters
1/2 Tbs. unsalted butter
1/2 cup coarse fresh breadcrumbs (use GF bread if necessary)
1/4 cup chopped walnuts
balsamic reduction, if desired

Heat the oven to 400°F. Line two rimmed baking sheets with parchment. In a large bowl, whisk 1/8 cup of the olive oil with the mustard, Worcestershire sauce, 1/8 tsp. of the salt, and about 5 grinds of pepper. Add the Brussels sprouts and toss to thoroughly distribute the mustard mixture. Spread the sprouts in an even layer on sheets. Roast until the cores of the sprouts are just barely tender and the leaves are browning and crisping a bit, 20 to 25 minutes. While the sprouts are roasting, make the topping: Line a plate with two layers of paper towel. Heat the remaining 1/2 Tbs. oil with the butter in a medium (10-inch) skillet over medium-high heat. When the butter has stopped foaming, add the breadcrumbs all at once; toss to coat with the fat. Reduce the heat to medium, add the walnuts and the remaining 1/4 tsp. salt, and cook, stirring constantly, until the crumbs are browned and slightly crisp and the nuts are golden, 4 to 6 minutes. Dump the breadcrumb mixture onto the paper towels to drain the excess fat. Transfer the sprouts to a serving bowl and season to taste with salt and pepper if necessary. Drizzle with balsamic reduction, if using.  Sprinkle the crumbs over the sprouts just before serving.