Preheat the oven to 180 degrees Celsius. Rub pumpkin with a little olive oil and roast for 20-30 minutes, or until softly roasted.
Drain the chickpeas, reserving 3 tablespoons of water from the can. Put the chickpeas and water in the food processor and process until smooth. Add pumpkin, garlic, tahini and lemon juice and continue to process. With the processor running, add the chilli oil and then slowly pour in the olive oil. Continue to process until the hummus has lightened in colour and turned really creamy in colour and texture. Season to taste.