Chop up the sausage, potatoes, and brussels sprouts. The sausage should be sliced, potatoes should be cut into 1/2" thick pieces to ensure they are fully cooked in 35 minutes, brussels sprouts should be halved (with the ends trimmed and discarded).
Preheat oven to 400 F
Lay a piece of parchment paper on to a large baking sheet. Add the sausage to the top area of the sheet pan.
Make the garlic butter by combining the butter, olive oil, garlic, and seasonings in a bowl. Microwave it for 10-15 seconds so that the butter melts enough and becomes liquidy when mixed.
Add potatoes and brussels sprouts to the sheet pan and pour the garlic butter on top of them. Mix the butter into the vegetables with tongs or a spatula. If you are using pork or beef sausage, you do not need to add any oil to the sausage as it has enough in it to cook. If you are using turkey or chicken sausage, you can add a little olive oil on top.
Bake for 35 - 38 minutes or until potatoes are done. Add some fresh herbs on top. My favorite to use are chives!
Serve with a dipping sauce of your choice!