Preheat the oven to bake at 400 degrees.
Place your halved brussel sprouts & cauliflower in a bowl (if you pull apart the cauliflower head with your fingers instead of chopping it makes less of a mess). Drizzle with a little olive oil and sprinkle with your garlic salt, rosemary, and generous amounts of salt & pepper. Gently mix together with your hands and place on a large baking sheet.
Drizzle the tops of all the vegetables with maple syrup and place in the oven. After 15 minutes mix in your pistachios and give the vegetables a gentle stir. Let them roast for another 15 minutes or until cauliflower stems become soft and brussel sprouts slightly brown.
Serve as a side dish or in a bowl over some warm grains or quinoa.