Yield 4 servings
2 small red onions, sliced into ½"-thick wedges
1 fennel bulb, sliced into ½"-thick wedges
6 Tbsp. extra-virgin olive oil, divided
Kosher salt, freshly ground pepper
8 oz. hot or sweet Italian sausage (about 2 links), casings removed
10 oz. gemelli, casarecce, or other medium pasta
1 tsp. finely grated lemon zest
2 Tbsp. fresh lemon juice
6 cups baby arugula
Finely grated Parmesan (for serving)
- Preheat oven to 425°. Toss onions, fennel, and 2 Tbsp. oil on a rimmed baking sheet; season with salt and pepper. Spread out into a single layer. Pinch sausage into small pieces and scatter around onions and fennel. Roast until vegetables and sausage are cooked through and well browned, 25–30 minutes.
- Meanwhile, cook pasta in a large pot of boiling salted water, stirring occasionally, until al dente. Drain, reserving 1 cup pasta cooking liquid.
- Combine vegetables, sausage, and pasta in a large bowl. Add lemon zest, lemon juice, remaining 4 Tbsp. oil, and ¼ cup reserved pasta cooking liquid and toss to coat, adding more pasta cooking liquid if needed, until sauce comes together and coats pasta. Toss in arugula.
- Divide pasta among plates and top with Parmesan. Season with more salt and pepper.