Pull leafy greens away from tough stems and transfer greens to a large sink, discarding stems.
Cover greens with water and with both hands, rub and toss greens in water to remove dirt and grit. Drain water and repeat process 3-5 times until greens are clean and no dirt is evident in water. Roughly chop cleaned greens by rolling bunches of leaves up and slicing with a sharp knife.
Heat butter and oil in a large stock pot or dutch oven over medium high heat. Add onion and saute for 2-3 minutes. Add garlic and saute until fragrant.
Add greens in three batches, stirring with a wooden spoon after each addition to wilt greens. After all greens have been added, pour in stock and stir to incorporate. Bring greens to a boil.
Once greens come to a boil, reduce heat to medium and add spices, brown sugar, liquid smoke and vinegars. Stir to incorporate all ingredients. Cover pot and simmer for 30 - 45 minutes, stirring occasionally.
Check flavor and consistency of greens after about 30-45 minutes of cooking. Add more seasoning to taste. Replace lid and continue cooking for another 30-45 minutes, depending on desired level of tenderness.
Once greens have reached your preferred level of tenderness, transfer them to a serving bowl with some of the cooking liquid. Top with a few dashes of hot sauce before serving if desired.