For the fregola:
heat the fregola in a saucepan, add the salt and cook, adding boiling water little by little.
Leave to dry, remove from the heat and add the butter, Grana Padano and vinegar. Divide the fregola into buttered disposable molds. Keep warm.
For the sauce:
reduce the tomato juice by 2/3, add the extra virgin olive oil and salt.
For the finishing:
arrange the fregola in the center of the plates, then the sauce and finally the caviar and sugar