Place the noodles in a large bowl. Cover with warm water and allow to sit for 20 minutes. Drain and pat dry. In a wok, over medium heat, add the oil. When the oil is hot, add the shallots, peas, mushrooms, garlic and bean sprouts. Season with the fish sauce and black pepper. Stir-fry for 1 minute. Add the crabmeat. Season with the fish sauce and black pepper. Continue to stir-fry for 2 minutes. Add the noodles and green onions. Stir-fry for 1 minute. Remove and serve on a large platter.