Roast the pumpkin using this method

Drain the boiled chickpeas (use the water for making dals or dough. It is very nutritious) and peel the outer covering of all the chickpeas.

Grind the pumpkin, chickpeas, pumpkin seeds, garlic and cumin in a food processor or a mixer until it is almost smooth. Add the lemon juice and grind further until well combined.

With the motor running, add the olive oil in a thin steady stream until smooth.

Transfer the hummus to a serving bowl, pour a little more olive oil on top and sprinkle the sumac. Serve with lavash or pita chips or store in an airtight container and use as a spread as needed. This will stay good in the fridge for a week.