I nord Italiani preferiscono la base di burro per le salse

I'm adapting a recipe from "Marcella's Italian Kitchen".  Next step, saute butter and finely chopped onions over medium heat, stirring well for one minute, then cover the pan, turning down to low.  The onion must turn very pale gold, not brown. This recipe calls for 6 tbsps butter and 3 cups finely chopped onions. Marcella is from Venezia in northern Italy and this butter based sauce reflects her regional preference. Southern sauces tend to favor an oil base.