Bourbon and brown sugar collards: if using collard bunches or bundles, remove stems from greens and discard.
Roll up collard leaves like a cigar and slice them into ribbons around a half-inch wide.
In a large pot over medium heat, add bacon. Render bacon until crisp about 6 minutes. Then add and cook the onions until they are soft, about another 5 minutes.
Add garlic and cook for 1 or 2 more minutes.
Add brown sugar, apple cider vinegar, chicken broth, and bourbon to the pot with the bacon, onion, and garlic. Stir everything to combine.
Season with a good pinch of salt and black pepper. Bring everything to a simmer and stir in the collard greens in batches.
Cover and cook for 1 1/2 hours, stirring occasionally until collards are tender and soft. Near the end, taste for seasoning and add any salt or black pepper that might be needed.
Make the mayonnaise: add all mayo ingredients to a small food processor or cup for an immersion blender and blend to combine. If you do not have a blender, you can mince the peppers into very very fine dice and stir everything together.
Store pickled pepper mayonnaise in a sealed container in the refrigerator for no more than 2 weeks.
Sandwich assembly: add 3 or 4 spoons of collards and about 15 or 20 cannellini beans into a skillet over medium heat. You aren't trying to cook anything; you just want to warm everything through at this point.
While the collards and beans are warming, spread pickled pepper mayonnaise on one side (the inside) of two slices of bread.
Add half of your shredded cheese to one slice on top of the mayo.
Top the shredded cheese with the warmed-up collards and beans and then top with the rest of the cheese. Add a few shakes of your favorite hot sauce if you want. Sandwich the second slice on top of everything to complete the sandwich.
Spread half of your butter on the top of your sandwich.
Wipe out the skillet that had the collards and beans in it and place it back over medium heat.
Very carefully flip the sandwich over and place it butter-side down into the warmed-up skillet. Spread the other half of your butter on what is now the top of the sandwich.
Cook the first side for 3 to 4 minutes and then flip.
Cook on the second side for an additional 2 to 3 minutes and continue carefully flipping until the sandwich is brown enough to your liking.
Once the outside of the sandwich is toasty and golden brown, serve and enjoy.