1. Put plenty of water in a pot and add 1 teaspoon of salt and the vegetable stock cube. When the water boils, add the spaghetti. Cook for one minute less than the time indicated on the package. Reserve about 1 cup of the cooking water and drain the pasta.
2. Heat the olive oil in a large, deep skillet over medium-high heat. Add the onion and sauté until it becomes translucent and sweet. Add the garlic and stir for a few seconds, just until fragrant.
3. Add the seafood and sauté until it colors and its liquids evaporate. Deglaze with the wine or ouzo and let the alcohol evaporate for a minute or two.
4. Add the cherry tomatoes, grated tomatoes, the remaining salt, and pepper. Cook for three to four minutes, until the cherry tomatoes soften and release their juices, creating a light, aromatic sauce. If needed, add a little of the reserved pasta water to help the sauce 'bind' better.
5. Add the spaghetti to the skillet and toss to coat well with the sauce. Turn off the heat, add the parsley, lemon zest, and stir one more time. Serve immediately, with extra parsley and chili flakes, if desired.
