Potato gnocchi with tomato sauce with onion and butter

Drop the tomatoes into boiling water for one minute, drain in a colander, and skin them once cool enough to handle.

Wash the tomatoes in cold water, cut lengthwise and remove the stem.

Put the tomatoes in the saucepan, cover, medium heat, 10 minutes.

Pass the tomatoes and their juices through the food mill, turning clockwise and counterclockwise to loosen; use a disc that holds back the seeds. Roughly chop the pieces that do not pass through.

Into the saucepan add the butter, the onion peeled and halved, and salt to taste.

Hold at a slow, steady simmer uncovered for 45 minutes, stirring from time to time and mashing large pieces of tomato with the back of a wooden spoon.

Boil the waxy potatoes in a Dutch oven of water until tender, about 20 minutes.

Peel the potatoes while hot and puree them through the food mill while still warm.

Add most of the flour and knead into a smooth mixture; stop adding flour when the mixture is soft and smooth, since some potatoes absorb less flour than others.

On a lightly floured surface, roll into sausage-like ropes about one inch thick and slice into three-quarter-inch pieces, dusting hands with flour.

Press each piece against the inside curve of a fork just below the prongs and flip it toward the handle to make grooves; hold on floured wax paper.

Check the sauce, which reduces from watery to thick; adjust salt.

Drop the gnocchi into generously salted boiling water without crowding; once they float, wait about 10 seconds more, two to three seconds longer if floury.

Remove the onion from the sauce.

Layer sauce, gnocchi and Parmesan, repeat, finish with more Parmesan on top and turn rapidly with a spoon to coat.