Heat oil in a large heavy-bottomed pot and sauté the garlic. Be careful not to burn the garlic; it will ruin the sauce.
Drain the tomatoes reserving the juice.
While the garlic is cooking, start the de-seeding process and add to the pot when the garlic is golden. Then, keep de-seeding the tomatoes and add the pulp to the pot.
Add the reserved tomato juice, Sachet, chicken stock, and sugar.
Bring to a boil, reduce heat, and simmer until the sauce is reduced by half. This will take anywhere from 2-3 hours, stirring every once in a while.
When the sauce is finished, remove the Sachet.