Heat the oil in a heavy saucepan over medium heat. Add the onion, capsicum, garlic, chilli flakes, oregano and bay leaf. Cook and stir until the onion is tender.
Stir in the eggplant, tomatoes (with liquid), tomato paste, mushrooms and anchovies. Cover and simmer over low heat until eggplant is tender, about 30 minutes. Stir frequently. When the eggplant is tender remove the lid and cook until most of the liquid from the tomatoes has boiled off. Season with salt and pepper to taste.
While the sauce is simmering bring a large pot of lightly salted water to a boil. Add the pasta and cook for 4 minutes or until tender. Drain and stir in the eggplant gravy.