Use your Roma Strainer and Sauce Maker to remove the skins and seeds from the tomatoes.
Stovetop method: Using a paring knife, score an "x" in the skin on the bottom of each tomatoes to make peeling easier. In a large saucepan, bring several cups of water to a boil. Plunge tomatoes into boiling water for a slow count of 3 to 5. Remove from water, and starting at the "x" use a paring knife to peel the skin from the tomato. Slice the tomato in half and squeeze out the seeds from the fruit. Using a food processor or blender, pulse to chop tomatoes to desired consistency.
To Make SauceHeat olive oil in a large saucepan over medium-low heat. Add the onions, garlic, celery, and carrots, cover and cook for 15 minutes, stirring occasionally. Uncover and cook for an additional 5 to10 minutes or until vegetables are soft and slightly golden. Add the tomatoes, sugar, coriander, marjoram, oregano, basil, salt, pepper, and red pepper flakes. Bring to simmer and taste for seasoning. Re-season as desired. Cover and simmer for 15 minutes. Remove from heat and use with pasta, as a dipping sauce, or as desired.