Cut onion to julienne and divide basil in 2/3 parts and fried everything in a pan with olive oil, 1 teaspoon of sugar and 1 teaspoon of salt. The flame has to be around 270 watts.
Mashed the tomato base with the blender on a medium consistency. When onion is soft, put the tomato base in the pan and rinses the boll (or the can) with a little bit of water. Reduce the flame to 210 watts.
During the cooking, after 15 minutes add 1 teaspoon of sugar. At the end, after around 15 minutes add 1 teaspoon of salt and 300 gr of water.
When the water disappeared, turn off the flame. The portion is between 110 and 120 gr for jar/cup