Place the chicken in a shallow bowl and spoon over the black bean sauce. Leave to marinate for 30 minutes.
Bring a large pan of water to the boil and tip in the rice. Return the water to the boil and stir well. Lower the heat to a fast simmer and cook for 10 minutes.
Cook the chicken under a medium grill for 5 minutes each side or until chicken is cooked.
Heat the oil in a large saucepan and cook the mushroom for 2 minutes. Add the onion and fry until soft but not coloured.
Add the garlic and tomatoes and cook for 1 minute. Add the stock and grape juice and simmer for 5 minutes.
Drain the rice and add the rice to the mushrooms mix and heat through. Season with pepper and salt.
Serve the rice topped with the chicken and garnish with a sprig of coriander.