Add the olive oil to a large frying pan or Dutch oven set over medium heat. Gently sauté the garlic for about 30 seconds, ensuring it doesn't burn. Toss in the oregano and dried chili flakes, followed by a pinch of salt, and cook for another 30 seconds.
Next, pour in water and tomato sauce, and add the spaghetti, ensuring it's completely submerged. If you're using a Dutch oven or pasta pot, use boiling water to help the pasta soften more quickly.
As the liquid starts to boil, carefully stir the pasta from the bottom up to prevent sticking. Keep a watchful eye on your spaghetti, and continue to stir it throughout the cooking process, which should take about 10-12 minutes. With constant attention and patience, you'll have perfectly cooked spaghetti ready to enjoy!
Notes
If, for some reason, your pasta is too al dente, add half a cup more water.
Another tip is to cover it, as the heat in the pot will finish cooking it.
If you have leftover pasta, store it in the refrigerator in a tightly closed container.
Reheat it in the microwave or on the stove in a pan with one or two tablespoons of water so that it does not stick.