A Gastric with nolly prat is the basis for fresh sour sauces:
180 grams shallot coarsely chopped
1 dl tarragon vinegar
0.5 liters of white wine
180 grams nolly prat
1 bay leaves
Peppercorns
Combine all of this in a saucepan and reduce by half. Strain the liquid and it is ready to use