Soak the white beans overnight. The next morning, cook them for about an hour. Drain and reserve.
Bring two cups of water to a light boil. Add the collards and the lemon slices. Cook until the collards are tender but not falling apart--about five minutes. Remove the lemon, drain, and hold aside.
In a large saucepan, cook the pork cubes to render as much fat as possible, and to get them a little crisp. Add the flour and stir to make a light roux. Lower the heat, add the onions and the garlic, and cook until translucent.
Add the beef stock to the pot and stir to blend the ingredients. Add the thyme, birdeye pepper, cloves, the beans and collards. Bring to a light boil and lower to a simmer. Cool for about an hour and a half.
Cutting the potato into cubes. Add the potato and salt to the soup and cook about twenty minutes more. When the potatoes are cooked enough to eat without a crunch, the soup is ready. Adjust seasonings with salt and pepper sauce. Garnish with chopped parsley and serve.