1Bring a medium size pot of water to a boil. Add the plum tomatoes for 1 min. Transfer them to a cutting board and let cool. Once ready to handle peel off the skin. Grate the tomatoes with stainless steel box grater using the largest grain.
2Heat 1 tablespoon olive oil in a large saucepan over medium heat. Stir in the diced onions and garlic, season with 1 teaspoon kosher salt and cook until translucent for 4-5 minutes, and add the grated tomatoes. Cook for 10 min and add the roasted peppers. Raise the heat and cook while stirring, for another 5 minutes
3Pour the vegetable broth, bring to boil, then lower the heat to simmer and cook it for another 1.5 hours, while occasionally stirring the mixture, so it doesn’t stick to the bottom of the pan, until the sauce thicken slightly.
4Bring a pot of 6 quarts of salted water to a boil. Cook the Spaghetti until al dente, folloing the package instructions. Drain well using a colander and transfer the pasta to the pan with the tomato sauce. Toss it gently to evenly coat the spaghetti with the sauce. Transfer the pasta to a pasta bowl, garnish with basil and serve immediately.