Is it correct? Our best-selling product or our best seller is wings.

Yes, that is correct. "Our best-selling product" or "our best seller" refers to the product that sells the most or is the most popular among customers, in this case, wings.

Both "our best-selling product is wings" and "our best seller is wings" are correct and commonly used phrases, with slight differences in emphasis:

- Our best-selling product is wings: This phrase emphasizes that wings are the product that sells the best out of all your products. It focuses on the sales performance of the product.

- Our best seller is wings: This phrase is more casual and colloquial. It also indicates that wings are your most popular product but puts more emphasis on its popularity with customers.

In general, both phrases convey the same meaning: that wings are your top-selling product or item.