Mashed Potatoes with so much cream

Late last night the urge struck to make something - anything - delicious, and we ended up settling on mashed potatoes. I had never made mashed potatoes before, but it turned out to be obscenely easy. We cut into chunks and boiled 10 small russets, and sauteed several cebollas de ribo verde (small white onions w/ green stems) in another pan. When the potatoes were cooked we drained them and mashed in a few tablespoons of butter, about 2 cups of heavy cream (...) and the cooked onions, as well as about 1/4 cup grated Pecorino Romano. Tiffany was appalled at the amount of cream, but those who didn't see how much went in ate away happily and without guilt - delicious!