In a saucepan, warm the oil over medium heat. Add the onion and bell pepper and cook until softened, about 5 minutes. Add the garlic and mushrooms and cook until mushrooms have released their juices, about 5 minutes.
Add the tomato paste, salt, cumin, cinnamon, and turmeric and cook, stirring constantly, for 1 minute to toast the spices and coat the onions in the tomato paste.
Add the tomatoes and stock. Bring to boil, then reduce the heat to low and simmer, covered, for 15-20 minutes or until the water is absorbed and bulgur is cooked. Season with more salt and pepper, to taste.