This is usually accomplished by placing the rock upside-down in a weak, continually stirred acid, so that any debris can be washed away.
Cook over medium-low heat, stirring continually, until the soap completely dissolves.
Bring to simmer over moderate heat, stirring continually.
Add a half-cup hot cooking liquid and simmer, stirring continually, until it has been absorbed.
Cook, stirring continually, until vegetables are coated with fat and give off liquid, about 30 minutes.
This mixture is then mixed and continually stirred for half an hour.
Add a cupful of hot stock and cook, stirring continually, until the rice has absorbed the liquid.
Slowly add the cornmeal while stirring continually.
Add wine and bring to boil, stirring continually.
Simmer until it has been absorbed, stirring continually.