Yes, you can overcook Irish stew. Although stews take quite a bit to soften and break down, it’s also possible to overcook them. In that situation, the vegetables begin to fall apart. Instead of biting into slightly firm potatoes or carrots, you’ll see broken pieces of dissolving vegetables. The broth can also take on a bitter, overly salty flavor that is unpleasant. For this vegan Irish stew recipe, it’s best to slow cook on high for 6 hours or until the potatoes and carrots are fork-tender.