Cut beef into 3 cm chunks or thereabouts. Let beef soak in a bowl with the tomatoes and juice, lemon juice, mushrooms, black pepper, crushed chilis and onions over night. Brown the meat in a skillet. In large pot throw in the tomatoes and crushed chillis, onions, meat, paste, everything except the beans and peppers and slow cook for three hours. Next chop your green and red peppers into long slivers or if you prefer diced. Also stir in your beans and cook slowly for one more hour. All cooking must not have the lid on. With the thick "soupy" ring around the pot; stir back into the simmering chili.
You might like the chili hotter or maybe milder, depends on your taste. What ever you do, don't ruin the chili by making it hotter with hot sauces, this has a tendency to make the chili into "superficial" body heat not a deep solid heat. To accompany the chili try and get your hands on some "Agua Dente" (fire water) 80% alcohol (national drink in Colombia). I guarantee you will see God!