Preheat the oven to 400F. Place the potatoes on a baking sheet and sprinkle with the olive oil, salt & spices. Toss to evenly combine then spread into an even layer on ⅔ of the baking sheet. Bake the potatoes for 20 minutes.
After 20 minutes, remove the sheet from the oven and flip the potatoes. Place the brussel sprouts on the remaining ⅓ of the baking sheet and sprinkle with the olive oil, lemon juice, salt and cayenne. Toss to evenly combine.
Place the sausages on top of the vegetables. Bake everything for another 20-25 minutes, stirring the brussel sprouts often. Serve and enjoy!