Cook the rice in boiling salted water for about 20 minutes. Wash turkey breast, dab dry and cut into pieces. Peel and finely dice onions. Drain mushrooms. Heat oil in a pot.
Brown the meat in it thoroughly. Add the onions and mushrooms and fry. Season with pepper. Add stock, bring to the boil and cook everything for about 10 minutes. Add peas to the meat. Mix cream and flour and thicken the ragout with it.
Season to taste with salt, pepper and lemon juice. Drain the rice on a sieve. Serve the turkey ragout together with the rice. Garnish with lemon and parsley.