Cut the top off the pumpkin, about two-thirds of the way up. Remove the pumpkin seeds, then scoop the flesh out of the bottom and the lid.
Heat oven to 200C/180C fan/gas 6. Cut the pumpkin flesh into pieces and put in a roasting tin with the garlic and a good glug of oil. Season, then bake for 45 mins until very tender. Leave to cool.
Tip the pumpkin into a food processor with any juices from the roasting tin and the garlic. Add the lemon juice, tahini paste and chickpeas. Season with salt and blend to a paste – add a little more oil if it's too thick. Scoop the hummus back into the pumpkin and serve with the peppers, breadsticks and pitta chips.