Preheat the oven to 425 degrees F and get out a large sheet pan. Remove any wilted or damaged leaves from the sprouts and slice them in half. If using sprouts from frozen, thaw ahead of time to the point they can be sliced. They do not need to be thawed completely to proceed; they need to not be marbles anymore though.

Put the halved sprouts on the sheet pan and drizzle about 2 tbsp olive oil over top. Toss to coat before laying the sprouts out cut side down. Roast for 10-12 minutes in the preheated oven, then flip each and every sprout over so the cut side is up, and then roast for 10-12 minutes more, until they are well browned. Sprinkle them with salt when they come out of the oven.

After the sprouts get their flip is the right time to make the sauce. Combine the olive oil (3 tbsp), dijon, mayonnaise, red wine vinegar, salt, pepper, sugar, and garlic powder in a small bowl or measuring cup and stir well to combine.

Prepare the mashed potatoes so they are hot and ready to go when the sprouts come out of the oven. Assemble the bowls by scooping potatoes in the bottom of a bowl and topping with the sprouts. Drizzle the sauce over top and prepare to delight.