Boil pumpkin for 20 minutes, or until soft. Or roast in the oven for more flavor.
Meanwhile cut all veggies.
When pumpkin is almost soft, heat cooking oil over medium heat. Saute onion for 2 minutes, add garlic and cook for 2-3 minutes more. Stir regularly.
Add tomatoes, thyme, and sage. Stir well and cover. Cook for 10 minutes, stir occasionally.
Meanwhile, drain pumpkin and blend in a food processor until smooth. If you roasted the pumpkin blend with a little water.
When tomatoes are soft, add pumpkin puree. Season with salt and black pepper to taste. Stir well and cook for 15 minutes more. Add water if needed.
Cook pasta in lightly salted water, according to the package
Heat a skillet with cooking oil over high heat. Cook chicken until lightly browned.
Last 5 minutes add chicken and kale to the sauce.
Top pasta with the sauce and grated Parmesan, if using.