The beauty of homemade sauce is that I have complete control over the ingredients, which means I can create a sauce that’s not only delicious but also nourishing. I know exactly what’s going into my sauce, and I can adjust my recipe as I desire: more salt, more veggies, less meat, more meat, etc.
Heat the olive oil in a large skillet or Dutch oven over medium-high heat. Brown the sausage in the skillet. Once the sausage is slightly brown (there may still be a bit of pink, it's okay!), add the onions and mushrooms. Saute the veggies for 3-4 minutes, until the mushrooms are brown and the onions are translucent. Add the minced garlic and dried oregano, and saute for 1 minute, just until fragrant. Now add the red wine to the ingredients, and stir. At this point I like to gently scrape the skillet with a wooden spoon to remove any of the bits that may be stuck at the bottom. There's incredible flavor in the little bits.
Finally, add the remaining ingredients: fresh basil, tomatoes, tomato paste (see note below), and salt. Using the back of a fork, crush any of the large tomato chunks to help smooth out the sauce. The saltiness of your sauce may vary depending on the seasoning used in your sausage. The first time you make this sauce I recommend using 1/2 teaspoon of salt, and then increasing the salt to your desired taste after the sauce simmers.
Simmer the sauce, covered, over low heat for about 20-25 minutes. This allows the flavors to "marry" together, and also thickens the sauce if you used tomato paste. I like to check on my sauce at the 15 minute mark, just to make sure it's not getting too thick. If you find your sauce is getting too thick for your liking, add a small amount of water (or more wine ;)). Before serving the sauce, give it a taste and adjust the salt to taste. If you find your sauce is a bit too acidic (depending on the tomatoes), add a pinch or two of sugar.
Serve the sauce over spaghetti noodles, and top with freshly grated parmesan cheese and extra basil. The sauce will last in the fridge for 3-4 days.