Place the tomatoes in the water a few at a time. After no more than 60 seconds, remove the tomatoes. When they have rested for about 60 seconds the skins will slip off easily. Place the skins in a bowl. Repeat until all of the tomatoes have been skinned.

Chop the tomatoes coarsely.

Place the oil in a large skillet and heat over a medium-high heat. Reduce the heat to medium and add the garlic. Cook gently for about 3 minutes. Do not allow the garlic to turn brown.

Add the onions and cook until they are translucent. Stir frequently and do not allow them to brown.

Add the tomatoes and stir well. Place the tomato seeds and skins in a fine mesh strainer and strain the juice into the pan by pressing on the pulp. Cook the tomatoes until they are soft (about an hour).

Remove from heat, add the salt and puree until smooth, using a stick or conventional blender.