Heat 2 tablespoons oil in a heavy large saucepan over medium-low heat. Add onion and cook, stirring occasionally, until softened, about 7 minutes. Add rice and cook, stirring constantly, until rice is translucent, about 5 minutes.

Add 1 cup broth and cook, stirring, until mostly absorbed, 5 to 7 minutes. Add ½ cup more broth and cook, stirring, until mostly absorbed. Repeat once, then add squid ink and stir to combine. In ½ cupfuls, add remaining broth, stirring until each addition is mostly absorbed before adding the next, until rice is tender yet still slightly firm to the bite (you may not use all the broth). Remove from heat, season with salt to taste and cover for warmth.

Heat remaining 1 tablespoon oil in a large skillet over high heat until hot but not smoking. Add squid and cook, stirring, until opaque, about 3 minutes; season with salt. Stir squid and any liquid from pan into risotto, thin risotto with a little broth if desired. Serve immediately, garnished with parsley.