Tomato Sauce

We use lots of tomatoes around here.  We thought we'd give you a short post about how to turn those diced tomatoes into tomato sauce.
I usually use about 1 kg of tomatoes and get about 1 1/2 cups of sauce.
First, blanch, slice, and seed the tomatoes
This is done by slicing an X on the top and bottom of the tomatoes(just through the skin) then dropping them into boiling water until the peeling just begins to lift off of the tomato around your cuts(between 10-30 seconds). Next, immediately remove the tomatoes from the boiling water and drop into ice water to stop the cooking process.  Now the skin should peel right off possibly without the help of a knife leaving the flesh of the tomato for you. I normally slice the tomatoes along the previous X into 4 pieces.  I then cut out the seed part in the middle- you can either toss this or you can put it in a mesh strainer over a bowl to get the juice without the seeds.  At this point you should have something like this bag of blanched, sliced, and seeded tomatoes on the left.

Place the slices in a skillet with a few tablespoons of Olive Oil.
I generally start this cooking with both the olive oil and
tomatoes cold and let them heat up together.

Cover and cook over low/medium heat.

Stir occasionally and let the tomatoes cook down.

Transfer to a bowl or jar and set aside.  Note:  this doesn't keep long, so only make it a day or two in advance.