Drain mushrooms, reserving liquid. Over medium heat, cook mushrooms and peppers in butter until tender. Stir in flour and pepper. Cook over low heat until smooth and bubbly, stirring constantly. Slowly stiri in bouillion, milk, water, and reserved mushroom liquid. Bring to a boil over medium heat, stirring constantly. Boil and stir 1 minute. Reduce heat to low and stir in chicken, pimiento, peas and any other vegetable you desire. Cook until thoroughly heated through. Serve over baked puff pastry shells.