01 -
Bring a large pot of salted water to a boil. Add rigatoni and cook until al dente, about 10–12 minutes, or as package directs. Reserve 1/2 cup pasta water before draining. Drain and keep warm.
02 -
While pasta cooks, heat unsalted butter and olive oil together in a large skillet over medium heat. Add finely chopped onion and sauté for 3 to 4 minutes until translucent. Stir in minced garlic and chopped sage, then cook for 1 minute until aromatic.
03 -
Add pumpkin puree to skillet and stir thoroughly to combine with aromatics. Gradually pour in heavy cream while whisking for a smooth, cohesive mixture. Reduce heat to low and simmer sauce for 5 to 7 minutes so flavors meld. Add grated Parmesan, nutmeg if using, salt, and pepper. Taste and adjust seasoning as needed. For thinner consistency, stir in small amounts of reserved pasta water.
04 -
Transfer drained rigatoni to the skillet. Toss gently so each piece is thoroughly coated. If sauce is too thick, add reserved pasta water as needed to achieve desired texture. Cook pasta in sauce on low heat for 2 minutes, stirring occasionally.
05 -
Portion pasta into bowls. Sprinkle with toasted pumpkin seeds, extra grated Parmesan, and top with crispy sage leaves if desired. Serve immediately while warm.