Start by pulling and tearing greens away from stems, then chop them by taking a hand full of greens, rolling them up, and cutting the rolls horizontally into 3 or 4, resulting in approximately 1½-inch pieces.
Next, place greens in a clean sink and wash them thoroughly with cold water removing all grit, sand, and debris until the water becomes clear. Set aside.
Place bacon in a medium pot over medium-high heat. Cook, frequently stirring, for 5-6 minutes or until crisp. Remove half the bacon from the pan and reserve it for later on.
Add onion, garlic, and thyme to the pot, and sauté until the onion is translucent and fragrant (3-4 minutes). Next, add the greens to the pot and cook, stirring for 2-3 minutes or until wilted.
Once mustard greens have wilted, add broth, Creole seasoning, pepper flakes, sugar, and vinegar. Stir to combine and bring to a simmer. Reduce heat to low, cover the pot, and continue simmering for 25-30 minutes or until the greens are tender. Uncover the pot, season with salt and pepper to taste, and add more broth if needed. Cook for an additional 2-3 minutes.
Sprinkle the rest of the bacon on top and serve.