Boil the pasta: Bring a large pot of salted water to a rolling boil. Cook pasta until just shy of al dente. Reserve 1 cup pasta water, then drain.
Sauté aromatics: While pasta cooks, warm olive oil in a large skillet over medium heat. Add onion and a pinch of salt. Cook 3–4 minutes until translucent. Stir in garlic, sun-dried tomatoes, and red pepper flakes. Cook 1 minute until fragrant.
Deglaze: Pour in white wine. Scrape the skillet to release browned bits. Simmer 2–3 minutes until the wine reduces by about half.
Build the sauce: Stir in broth, Italian seasoning, salt, and several grinds of pepper. Add cannellini beans. Simmer 3–4 minutes to warm the beans and meld flavors.
Creamy finish: Reduce heat to medium-low. Stir in heavy cream. Simmer gently 2 minutes until slightly thickened.
Add greens and pasta: Fold in spinach until wilted. Add drained pasta and Parmesan. Toss to coat, loosening with splashes of reserved pasta water until the sauce clings silkily.
Brighten: Stir in lemon zest and juice. Taste and adjust salt, pepper, or heat.
Serve: Top with extra Parmesan and basil. Serve hot.
Salt smart: Heavily salt the pasta water so the noodles carry flavor into the sauce.
Use pasta water: The starch emulsifies the sauce, giving it that glossy, restaurant-style finish.
Go low and slow with cream: Keep heat moderate after adding cream to avoid curdling or breaking.
Grate your own Parmesan: Pre-grated cheese often clumps and doesn’t melt as smoothly.
