Millet "gratin" with Brussel Sprouts

We altered this recipe from Food52

• 1cup uncooked millet
• Kosher salt, to taste
• 4tablespoons olive oil, divided (plus more for greasing)
• 2tablespoons balsamic vinegar
• 1pound Brussels sprouts, trimmed and thinly sliced
•  a few small pinches of red pepper flakes
• 5ounces aged vegan cheddar, shredded (yielding 1 1/2 cups) 
• 1/2cup GF panko breadcrumbs
• 1/2cup finely grated, pinenut parmesan
• Freshly ground black pepper

1. Heat oven to 400° F. Meanwhile, cook millet in the instant pot 18 minutes—or according to package directions.
2. Toss grains while still warm in a large bowl (or back in the pan if it’s large enough for mixing) with 3 tablespoons olive oil, balsamic, and a pinch or two of salt. (The balsamic will taste a bit strong at this point, but it’ll mellow in the oven and help cut through the gratin’s richness.). Toss in Brussels sprouts, and season with 1/2 teaspoon of salt (or to taste) and Aleppo pepper. Add shredded cheese, and toss again until evenly mixed. Transfer to a lightly greased 14-inch round pan, a 9x13-inch casserole, or an equivalently sized dish.
3. In a small bowl, combine panko, pecorino, and several grinds of black pepper. Drizzle 1 tablespoon olive oil evenly over panko mixture (otherwise it’ll clump) and using hands, toss together until evenly mixed. Spread evenly over the farro and Brussels sprouts.
4. Bake for about 25 minutes, or until the crumbs are golden and crispy. Serve warm.