Boil pasta in a pot of generously salted water. Cook according to package directions. Most chickpea pasta cooks in 6-10 minutes. Save 1 1/2 cups of pasta liquid before draining.
While the pasta is cooking, prep the chickpeas. Mash one can of rinsed and drained chickpeas in a bowl with a potato masher or large fork until lightly crushed.
Heat 2 tablespoons of olive oil in a 12-inch cast iron skillet over medium-high heat. Turn the heat to medium and saute the onion and garlic for about 2 minutes.
Add the chopped sage, crushed red pepper flakes (use a small amount to start-you can always add more later), and salt to taste. Sauté, then add the mashed chickpeas and continue cooking for another 2 minutes.
Add the mashed chickpeas, pumpkin puree, and reserved pasta water. Bring to a light boil, then simmer until most of the liquid has evaporated-about 5 to 10 minutes.
Add the cooked and drained pasta to the skillet along with the remaining 2 tablespoons of olive oil, half the chopped parsley, zest from the entire lemon, and juice from 1/2 of the lemon. Toss well to coat the pasta with the sauce.
Divide the pasta into 4 serving bowls. Top each bowl with 2 tablespoons Parmesan cheese, remaining chopped parsley, and extra chopped fresh sage. Season with additional salt and crushed red pepper flakes if desired.
Notes
Ingredient Swaps & Additions:
Swap the chickpea pasta with your favorite gluten-free pasta or regular pasta.
Add extra pumpkin puree (1 cup total) for more pumpkin flavor.
Make it vegan: Omit Parmesan cheese. Add nutritional yeast or cheese for extra umami flavor.
Want even more protein? Serve with grilled or rotisserie chicken, turkey sausage, or salmon.