Japan will grasp at any half-excuse to put curry-cooking in its RPGs. You'll find no blame from me; curry is awesome. Yesterday's Nintendo Direct presentation revealed curry-cooking is a big part of Pokemon Sword and Shield, doubtless because curry is a popular dish in the United Kingdom (which the Galar Region is based on).
The brief introduction we received on Sword and Shield's curry-making demonstrated all the weird stuff we can make curry out of, including berries. But sweetening your sauce with wild berries still isn't as weird as the revelation you can make sausage curry. Sure, sausage curry doesn't seem like a big deal—until you remember Sword and Shield take place in a Pokemon world. What are those sausages made of? Matter of fact, what's any meat product made of in Pokemon?
The easiest and most obvious answer is, "There's no shortage of Pokemon stand-ins for the domestic animals we humans breed for food." Pork? Tepig. Beef? Miltank. Fish? Cast an Old Rod into the water and wait for dinner (probably Magikarp) to bite on the hook three seconds later.
Is it wrong to scarf down Pokemon? I don't know. Maybe. All I know is it's a Houndoom-eat-Houndoom world out there, and I'm not about to make curry out of Oran berries when some hard-working Kanto farmer already took the trouble to slaughter and process a Spoink. In fact, Spoink leads a cursed existence: It must continue bouncing on its spring-like tail, or its heart will stop. Being killed for food is a comparative mercy.
For real though, actual animals exist in the Pokemon universe. I imagine Pokemon's meat products are largely non-sentient as a result. We shouldn't have to worry too hard about our sausage curry being made from Rapidash that are too used-up to be of any more use at the racetrack.
Don't get me wrong: Dark things happen in the Pokemon universe, and that includes the consumption of actual Pokemon. In Pokemon Gold and Silver, it's revealed people sometimes cut off and eat the tails of Slowpokes and then leave the poor beast to wonder "What just happened?" an hour later. But I don't believe anyone's making ground beef out of Bouffalant.
I still wonder what Mr. Mime tastes like. I'm going to guess 'tough and savory yet sickeningly sweet and leathery,' like overcooked hamburger wrapped in cake fondant.
We have a summary of the September 2019 Nintendo Direct if you want to get up to date. We also have everything you need to know about Pokemon Sword and Shield, except for "How does Yamper taste?" (Peppery, I imagine.)