Bring a large pot of water to boil, salt it, then add 1/2 to 1 pound of pasta. (Vary the amount depending on your preferred pasta-to-sauce ratio) When the pasta is tender but not mushy, drain it, reserving one cup of cooking water.
Cook 1 tablespoon minced garlic and 8 ounces chopped smoked sausage, like chorizo or kielbasa, in 2 tablespoons olive oil over medium heat, until the sausage browns, 8 to 10 minutes; remove. Add 1 pound chopped dandelion greens; cover and cook until wilted but still somewhat firm, about 5 minutes. Uncover, add a little pasta-cooking water, and continue to cook, stirring, until the greens are tender, about 5 more minutes. Toss with gemelli and the sausage, adding more olive oil if needed. Garnish: Freshly ground black pepper.