Introduction: Purgatory Burgers. This is a recipe for burgers and buns that look like roasted on hellfire...I got the inspiration for this recipe when I stumbled across an article about a Japanese food trend: Black hot dogs and burgers. The pictures were stunning and I was very intrigued to try to replicate the buns and burgers. The article mentioned the use of bamboo charcoal for the black food. I couldn't find bamboo charcoal here - but came up with an similar solution and I'm pretty happy with the results.I think these black burgers fit not only for Halloween - I bet you could find use for them at the first of April as well...  Step 1: The Magic Ingredient. I couldn't find bamboo charcoal  and had no desire to use artificial food color.So I decided to experiment with medicinal charcoal a.k.a. activated charcoal.Medicinal charcoal is traditionally used to treat diarrhea and poisonings. In the European Union it is also used as food colorant (known as additive E153). You can buy activated charcoal at the pharmacy.So far I made the black burgers two times, I used two different products: charcoal tablets and charcoal powder. I bought both at local pharmacies. The recipe worked with both, but I recommend the powdered charcoal, it's easier to handle and also cheaper (50 grams where about six or seven Euros). The tablets also gave the burgers a slightly sandy mouth feel (The tablets consist of charcoal, bentonite and cornstarch, I think the bentonite caused the sandyness...) When I bought the charcoal I asked the pharmacists about side effects and they told me to keep in mind, that medicinal charcoal could interfere with other medication and cause constipation.Which means: If you or your guests takes medication you probably should skip the purgatory burgers (or talk to a pharmacist/doctor first)People with digestive problems probably should as well rather stick to burgers from heaven...(If you follow the recipe you consume 1,25 grams charcoal in one burger.- to treat poisoning with charcoal you have to consume 0,5 to 1 gram per kilo of your bodyweight (for example a 150 pound person would have to consume between 35 and 70 grams of charcoal...- for treating diarrhea the daily dose is 1,5 to 4 grams)I never had any trouble after eating purgatory burgers (but I never had more than two at a time). If you are concerned about the effects of charcoal consumption you should ask your pharmacist about it.These wikipedia articles may give you some information as well: Activated charcoal and  Charcoal biscuitIMPORTANT: Please handle the charcoal powder with care. The charcoal powder/dust shouldn't be inhaled!ALTERNATIVES: Instructables member hughw99 suggested the use of squid ink instead of charcoal. You may not add additional salt when using squid ink, since it is already salty as he mentions.  Step 2: Bun Ingredients. The amounts I'm giving here are for just four burgers. You can of course double or triple the amounts if you need more...To make the burger buns you'll need:For the dough:- one and a half and a quarter cup  (250 grams) Flour- one teaspoon dry Yeast- half a cup (125 ml) of warm Water (not warmer than a hot shower - if the water is hot enough to burn you it will burn your yeast as well)- one and a half tablespoons of Sugar- half a teaspoon Salt- one teaspoon Medicinal Charcoal (2,5 grams) (this equals 10 tablets of the brand I used)- two tablespoon of Apple juice (or Water)For the bun topping:- Black Sesame SeedsTo brush the buns after baking:- one tablespoon of melted Butter Step 3: Dough Preparation I. Put the flour into a bowl.Mix the warm water, sugar, yeast and salt.Add the liquid to the flour and let it just sit like this until the next step is performed. Step 4: Dough Preparation II. I dissolved the charcoal in a tablespoon of Apple juice (I like the taste, you could use water as well). If you use charcoal tablets you should smash them in a mortal before you dissolve them.Add the charcoal slurry to the flour in the bowl and mix everything.Knead the dough for about five minutes (you could use a machine or do it by hand)Cover the bowl and let the dough rest at a warm spot. Depending on the temperature it takes about an hour for the dough to double in size. (The dough NEEDS to double in size.) Step 5: Bun Shaping. When the dough has doubled in size you can continue with the bun preparation process.Take the dough and knead it again. Divide it in four parts. Shape them into buns and place those on a baking sheet, covered with parchment paper.Wet the buns surface with water and sprinkle some black sesame seeds on top.Cover them with a clean tea towel and let the buns rest for about 45 minutes. Step 6: Bake and Add Glow. Bake the buns in the preheated oven:375° F / 190°C for 15 to 20 minutesYou might want to check on them after about 15 minutes. Since they are black it is kind of hard to tell when they are done...  Edit: Instructables member t.rohner made a great suggestion in the comments: Take a part of the uncolored dough to make a white control bun. Bake it together with it's black siblings. On white bun you will easily recognize the browning process and therefore find the right moment to turn off the oven!  Brush the hot buns immediately with some melted butter and let them cool down completely. Step 7: Black Bean Burger Patties Ingredients. You probably could use the charcoal to colorize real meat - but I've never tried this myself. I made black bean burger patties for my black buns. I added charcoal to the mashed beans because black bean burgers naturally just have a brown color.I used dried black beans since I couldn't find canned ones.You need:- half a cup of dried black beans- one teaspoon activated charcoal- one teaspoon of olive oil to fry the onions and about one tablespoon for frying the patties.- one onion, diced- one (or more) cloves of garlic, mashed- one egg- two tablespoons of breadcrumbs- one tablespoon of soysauce- about one teaspoon each of: ketchup, mustard, hot sauce, powdered paprika and cuminIt seems to me like the charcoal absorbs some saltyness and spicyness - the flavors aren't very intense in these burgers. You might add a little more spiciness to them than you usually would. Step 8: Black Bean Burger Patties Mixing. Meanwhile you can prepare the bean burger meat:Take half a cup of black beans and cook them in three cups of water until they are done, maybe almost overcooked.I used a pressure cooker and it took just 30 min but the time very much depends on the beans, it can take up to an hour... and even longer without an pressure cookerThe half a cup of dried beans resulted about one and a half cup of cooked beans.  I use just one cup of cooked beans for the patties.I mashed the beans with a fork.I fried the diced onion and the garlic in some olive oil until they started to brown and added them to the bean mush. Then I mixed in all the spices, the egg and breadcrumbs and the charcoal.This mixture gave me a nice and shapeable dough which I formed into patties. Step 9: Black Bean Burger Patties Frying. I fried the patties for about 5 minutes on each side on medium heat.  Step 10: Assembling. I'm pretty sure you know already how to assemble a burger. So just follow your instincts.I used tomatoes and lettuce and a fair amount of hot sauce - since I think burgers from purgatory need to be hot ;) Step 11: Further Reading. If this instructable sparked your interest in monochromatic food you should read this instructable to get even more inspiration.Or you could take a look at the work of the fabulous artist Sophie Calle. Her work "Chromatic Diet" is based on monochromatic meals (the rest of her oeuvre isn't about food but well worth to look into!).