Cooked vegetables are a superb addition to your dog's diet as they are full of fibre and a great source of phytonutrients, vitamins and minerals.
Dogs are lacking in the enzymes necessary to digest plant material so cooking Veges breaks down the cell walls and makes the nutrients available to your dog. Naturally they would be ingesting plant materiel that was already broken down in the gut of a prey animal - this is what we are trying to replicate. Raw green tripe does support digestion but remember if your dog is not consuming hide and hair from whole prey then they will need extra fibre to encourage intestinal cleaning and to add some bulk to their stools. This is where Veges have their role.
Start with a small amount to allow your dog to get used to them. Try pumpkin, squash, kumara, leafy greens, carrots, kale, green beans, broccoli. Please note do not feed Onion - toxic or Corn on the cobb - can become an obstruction.