Pour the oil into the big skillet, scatter the garlic slices in the oil, and set over medium-high heat. Cook for 1 1/2 minutes or so, until the slices are sizzling, then add and toast the peperoncino in a hot spot for another 1/2 minute.
3. Shake and stir the pan until the garlic slices are light gold and starting to darken. Immediately pour in the crushed tomatoes and stir in with the garlic. Rinse out the tomato can and bowl with 1 cup of pasta-cooking water [or regular], and dump it into the skillet too.
4. Raise the heat; sprinkle in the salt and stir. Push the stalk or sprigs of basil into the sauce until completely covered. When the sauce is boiling, cover the pan, reduce the heat slightly, and cook for 10 minutes at an actively bubbling simmer.
5. Uncover the pan and cook another 5 minutes or so. The sauce should be only slightly reduced from the original volume, still loose and juicy. Remove the poached basil stalk or sprigs from the skillet and discard (but save the sauce that's clinging to it), and keep at a low simmer until the pasta is ready.
6. To dress pasta with marinara sauce, toss and cook them together, incorporating the shredded basil. Remove the skillet from the heat and toss in the cheese just before serving.