Preheat the oven to 425 degrees F. Line a large rimmed baking sheet with parchment paper. 

Toss the potato chunks with 2 tablespoons of the olive oil and 1 teaspoon of the Creole seasoning, making sure to evenly coat. Arrange in an even layer on the baking sheet and roast for 10 minutes. Remove from the oven, turn potatoes as needed, then push the potatoes to one side of the pan. In a large bowl, toss the cabbage, carrots, and red onion with 2 tablespoons of the remaining olive oil, the kosher salt, 1/2 teaspoon of the pepper, and the sugar, making sure to evenly coat. Spoon the cabbage mixture onto the other side of the sheet pan. It will probably take up about 2/3 of the pan. Coat the tenderloin on all sides with 1 tablespoon of the oil and the mustard, then sprinkle with the remaining 2 teaspoons of Creole seasoning and the 1/2 teaspoon of black pepper. Place the seasoned tenderloin on top of the cabbage. Return the sheetpan to the oven and roast until a thermometer inserted into the center of the tenderloin registers 140 degrees F, usually about 30 minutes longer. The cabbage should be crisp-tender and the potatoes should be golden. Transfer the cabbage to a serving bowl (or to plates), and set the tenderloin aside to rest for 5 minutes before slicing to serve. While waiting for the tenderloin to rest, add the minced garlic to the potatoes on the baking sheet along with the last tablespoon of olive oil. Toss to coat and allow the potatoes to remain on the warm baking sheet until the garlic is fragrant and the tenderloin is ready to be served. 

While the tenderloin is cooking,  make the Creole Mustard Sauce:  Combine the shallots and white wine in a small saucepan and cook over moderate heat until the wine is nearly evaporated. Add the Creole and Dijon mustard along with the heavy cream and whisk to combine. Simmer until the cream has reduced enough to coat the back of a spoon, usually about 3 to 4 minutes. Season the sauce with salt and pepper to taste and keep warm until ready to serve the pork.