Roast the Brussels Sprouts: Preheat your oven to a hot 475°F / 245°C.
In a large bowl, toss the quartered Brussels sprouts with 2 tablespoons (30 ml / 1 fl oz) of oil and a generous pinch of salt.
Spread them in a single layer on a 13x9-inch baking dish.
Roast for 20-24 minutes, stirring once halfway through, until they are beautifully browned and tender.
Set aside to cool slightly.
Toast and Cook the Millet: While the sprouts are roasting, heat a large saucepan over medium heat.
Add the dry millet and toast, stirring frequently, for 6-8 minutes until it's golden and fragrant. Carefully pour in 2 cups (480 ml) of water and bring to a boil.
Reduce the heat to a simmer, cover the pot, and cook for 20 minutes, or until all the liquid is absorbed.
Transfer the cooked millet to a large serving bowl and let it cool for 5 minutes.
Make the Dressing: In a small bowl, whisk together the remaining 3 tablespoons (45 ml / 1.5 fl oz) of oil, balsamic vinegar, maple syrup, lemon juice, and lemon zest until well combined.
Combine and Serve: Add the roasted Brussels sprouts, toasted walnuts, dried cranberries, and fresh parsley to the bowl with the millet.
Pour the dressing over the top and gently fold everything together until well combined.
Season with additional salt and pepper to taste.
Serve warm or let it cool to room temperature.
