Chulin 7:3-4

Chulin 7:3

If one eats an olive-sized portion of the gid hanasheh, he receives 40 lashes. If he ate the entire gid hanasheh and it was smaller than the volume of an olive, he is still liable (despite its size because he ate the whole thing). If he ate an olive-sized portion from one thigh and an olive-sized portion from the other thigh, he receives 80 lashes (40 per sinew), though Rabbi Yehuda says that he only receives 40 lashes (because Rabbi Yehuda considers the prohibition of gid hanasheh only to apply to the right thigh).

Chulin 7:4

Let’s say that an animal’s thigh was cooked with the gid hanasheh. If the gid hanasheh imparts flavor, then the thigh is prohibited. This is calculated by considering meat the volume of the gid hanasheh and turnips the volume of the thigh. (If that volume of meat would impart taste to that volume of turnips, it is prohibited.)