Pasta wheat is partially cooked wheat grains from durum wheat grown in the Tours region of France. You can buy it at supermarkets and delis.
Bring 1 litre/1¾ pints water and the bouillon powder to the boil in a large saucepan. Add the pouches of wheat grain, tamping them down into the liquid with a wooden spoon. Cover the pan and boil over a medium heat for 18 minutes.
Meanwhile, melt 50g/2oz of the butter in a medium-sized frying pan over a low-medium heat. Tip in the shallot, garlic and celery, and gently fry for about 5 minutes, stirring occasionally, until the vegetables have softened a little but haven't coloured. Pour in the vermouth, turn up the heat and bubble until it has almost disappeared. Set the pan aside.
Remove the pouches of wheat grain with a pair of tongs and leave them to drain. Tip the peas into the stock remaining in the saucepan and simmer them for 2 minutes or until hot. Drain off the stock, reserving it, and leave the peas in the pan.
Cut open the pouches and tip the wheat grain into the peas, then scrape in the contents of the frying pan. Add the parmesan, parsley and the remaining butter, and season with plenty of black pepper – it's unlikely you’ll need more salt. Return the saucepan to a low heat and stir thoroughly until the cheese has melted and the 'risotto' is a loose, creamy mass, adding a spoonful or two of the reserved stock if required. Serve immediately.