For pumpkin purée, preheat oven to 180C. Place pumpkin, garlic and thyme in the centre of a large piece of foil, season to taste, fold to enclose then roast until pumpkin is very tender (1-1½ hours). Transfer pumpkin flesh to a food processor (discard skin, garlic and thyme), process until smooth, set aside.
For acid butter, simmer wine, onion, vinegar, thyme and bay leaf in a saucepan over medium heat until reduced by four-fifths (4-8 minutes). Gradually whisk in butter until sauce is emulsified and thick (2-3 minutes). Remove from heat, pass through a fine sieve into a container and refrigerate until firm (1½ hours).
For mojo sauce, process coriander, chives, mustard, cumin and vinegar in a small food processor until smooth, then, with motor running, gradually add oil in a thin steady stream until sauce is thick and emulsified, season to taste and set aside.
Combine risoni and 250ml chicken stock in a saucepan and bring to the boil over medium heat, stirring occasionally and then continuously towards the end of cooking otherwise it will stick, until stock is absorbed (8-10 minutes; you may need to add more stock if too thick). Add 1 cup pumpkin purée (reserve remainder for another use), stir to combine and warm through, remove from heat, add 75gm acid butter (reserve remainder for another use) and Grana Padano, season to taste and serve risoni dotted with mojo sauce and scattered with coriander shoots.
This recipe is from the April 2011 issue of Australian Gourmet Traveller.