Bring a large pot of salted water to a rolling boil, then stir in the black pasta. Cook until just al dente, about 9-11 minutes, until it feels tender but still has a slight bite. Drain and reserve about 1 cup of pasta water.
While the pasta cooks, heat a splash of olive oil in a wide skillet over medium heat. Add the chopped garlic and chili flakes, sautéing until fragrant and just golden, about 30 seconds. The garlic should smell aromatic and start to turn a light golden hue.
Add the squid ink to the skillet, stirring vigorously to combine with the garlic and chili. Pour in about 1/4 cup of reserved pasta water, stirring until the ink forms a glossy, smoky sauce that bubbles gently. Let simmer for 2 minutes for the flavors to meld.
Drop the drained pasta into the ink sauce, tossing gently with tongs or a pasta fork to coat every strand evenly. Cook together for 1-2 minutes, adding more pasta water if needed to help the sauce cling to the noodles and create a shiny, oily sheen.
Squeeze fresh lemon juice over the pasta, then sprinkle with chopped parsley. Season with flaky sea salt to taste, balancing the smoky, briny flavors with bright citrus and herbs. Toss again to combine all the flavors beautifully.
Transfer the pasta to serving plates, drizzle with a little extra olive oil, and serve immediately while hot. The pasta should be glossy, jet-black, with a fragrant aroma and a perfect al dente bite.
