Take the lettuce heads, clean, drain, chop and put into a saucepan with the butter, cover and let steam for a few minutes, then add the soup stock, add the rice and boil until the rice is soft. Strain through a sieve, or not, as one fancies, season with salt, pepper, return to the fire, add the cream, let it come just to the boiling point and serve.
Vaughan's Vegetable Cook Book (1919).