Place a rack in the centre of the oven and preheat to 400 degrees.
Peel and remove seeds from pumpkin and cut 1 cup into a chunky dice. Toss in 1 tablespoon of olive oil.
Spread out the pumpkin chunks on a baking sheet ensuring the pieces do not touch. This ensures they will caramelize and get crispy.
Bake squash until they are easily pierced by a fork or knife, 30-40 minutes depending on size. After 20 minutes, flip pumpkin chunks so they bake evenly on both sides.
Remove roasted squash from oven and let cool at least 30 minutes.
In a large non-stick skillet, add 1 tablespoon of olive oil and minced garlic. Fry for 1 minute on medium heat until browned. Add sliced bell peppers and cook for 2-3 minutes until tender.
Add dry sherry, harissa paste, tomato paste, whipping cream, cumin, paprika, salt and pepper. Stir on low heat for 2-3 minutes. Turn off heat once the sauce is thickened to your liking. If you prefer a thinner sauce add more sherry or vegetable stock.
Boil pasta according to package instructions until al dente. Strain pasta and add to harissa sauce.
Toss pasta in spicy harissa sauce then transfer to bowls. Sprinkle with feta cheese and serve hot.