Heat a dutch oven or large heavy bottomed pot over med/high heat.
Add the bacon to the pan and cooked, flipping once, until golden brown, about 10 mins.
Remove to a paper towel-lined plate to drain.
Leave the bacon drippings in the pot and add the onion.
Saute until softened and golden, about 10 mins. Stir in the garlic and cook 2 mins more.
Stir in the brown sugar, then deglaze with the vinegar.
Mix in the stock and bring to a boil.
Reduce to a very low simmer and stir in the greens and seasonings.
Cover and simmer until very tender, about 40 -45 mins.
Remove the lid and cook until the liquid is reduced by half, about 15 mins.
Crumble the bacon (reserve 2 Tbsp for topping) and toss into the greens.
Serve with the reserved crumbled bacon on top.