Part 3/6:
Start by heating a Dutch oven over medium heat. Coat the bottom with olive oil and add the diced onions, allowing them to soften for several minutes with a pinch of salt to release moisture. Next, introduce minced garlic and cook until fragrant.
While the onions and garlic are cooking, crush your plum tomatoes if using whole ones. Once the onions are soft, add the tomato paste, stirring until combined. Deglaze the pot by adding half a cup of red wine, scraping the bottom to release all the flavor.
Then, add your crushed tomatoes into the pot, enhancing the sauce's depth. If the sauce seems too thick, add a bit of water to reach your desired consistency.