For the marinade mix mustard sauce, lemon juice, salt, and black pepper powder in a bowl. Using a brush, marinate the ravas fish. In a pan, heat mustard oil and grill the marinated fish. Transfer the grilled fish to a plate. In another pan, add pasta sauce, blanched rice noodles, julienned red, yellow, and green bell peppers, salt, black pepper powder, and fresh cream. Toss well using a tong. Transfer the rice noodles in the serving plate, place the fish on it. Garnish with parsley leaves and lemon slice.