Preheat oven to 425°F (220°C). To make vinaigrette, whisk oil with lemon juice, garlic, salt, pepper and mustard. Stir in 1/4 cup (60 mL) grated cheese. Toss broccoli, cauliflower and Brussels sprouts with vinaigrette. Spread on large baking sheet.
Roast 35 to 45 min. until tender and lightly caramelized. Sprinkle remaining grated or shaved cheese over top. Serve warm or at room temperature.
Vegetables can be roasted earlier in the day and served at room temperature.