Questions & Answers about wǒmen shuàn yángròu.
In this sentence, 涮 means to swish thin slices of food briefly in boiling broth, usually in a hot pot.
So 涮羊肉 is not just cook lamb in a general sense. It specifically refers to the hot-pot style of cooking lamb by dipping or swishing it in the soup.
This verb is very common in food contexts, especially with 火锅.