Preheat the oven to 350ºF and line a baking sheet with a silicone mat or parchment paper.
To prepare the vegetables, cut the pumpkin and other veggies into big chunks. Place them on a tray and add a tablespoon of olive oil and half a teaspoon of salt. Mix well so that all the vegetables are coated with the oil. Arrange them on the tray in a single layer to ensure even cooking. To avoid burning the garlic, hide it underneath the tomatoes.
Place vegetables in oven for 20-25 minutes until browned.
Meanwhile, cook the pasta according to the package instructions, and reserve one cup of the pasta water before draining.
After cooking the vegetables, peel the garlic and blend it with the water used to cook the pasta.
After cooking the pasta, you can use the same pot to prepare the sauce. Simply add a tablespoon of olive oil, oregano and chili pepper flakes to the pot and let them cook for a minute until they release their aroma. Then, add the sauce to the pot and mix everything together well. Check the seasoning and add salt and pepper as needed. Finally, add the cooked pasta to the pot and mix it very carefully to make sure everything is well combined.