Sift flour and salt into food processor, slowly pour in the egg and yolks , followed by the olive oil. As soon as the mixture comes together into a dough, switch off the machine. Put the dough onto a lightly floured work surface and knead for 10-15 mins, until smooth. Wrap in cling film and chill for 30 mins.
Put all ingredients in food processor and whizz to a paste. Season. Transfer to a bowl and chill until ready to use.
Cut pasta dough in half and flatten slightly with a rolling pin. Pass through a pasta machine until about 0.5mm thick. With a 6cm pastry cutter, cut circle from pasta and, using your fingers, stretch it as thinly as possible. Brush edges with a little beaten egg and place a little of the filling in the middle. Fold pasta over to make a semi-circle, press edges together to seal, then fold the 2 corners up over the centre and squeeze together tightly. Repeat until all pasta and filling has been used.
Bring stock to the boil and drop in the tortellini. Simmer for about 4 minutes, until tortellini are tender. Ladle into bowls and serve with freshly grated parmesan and chopped flat leaf parsley.