Step #1 add oil to a sautee pan, & sautee the onion & garlic.
Step #2 in a big enough pot add your 3 tomato sauces, onion & garlic, & enough water to make it a nice consistency.
Step #3 Heat until hot enough to add the spices, sugar, salt, & pepper.
Step #4 Now depending upon what you want to do, try to do this as long as possible for extra flavor, heat the sauce to 160 to 190 degrees, can take from 45 mins to 2 hrs.