It's possible to buy raw minces without added veggies. I know that Natural Instinct do a range called "pure" which is just meat and ground bone
http://www.naturalinstinct.com/pure-dog-food/ and Nurturing By Nature don't add veggies to any of their minces as far as I know. I'm sure there must be other suppliers too.
Many raw feeders just feed meat, bone and oily fish, sometimes adding a raw egg once or twice a week and feeding green tripe a few times every week. The proportions should be roughly 80% muscle meat, 10% bone and 10% offal (typically liver and kidney), but you don't have to have that balance every meal. As long as you feed a wide a variety of meats and get the balance roughly right over a week they will get all the nutrients they need.
I choose to add blitzed, raw veg. to some of my dogs meals, but not all. If it's blitzed I believe they get nutrition from it and it's also really useful to bulk out meals if you have a dog that's prone to putting weight on and can help if you have a dog that's prone to constipation. I don't add fish oil because they have oily fish every week and I don't add all the other stuff that Nutriment do because I don't think they need it.
When I blitz raw veg. at home I use a mix of things like carrots (I know you can't), broccoli, green beans, peppers, tomatoes, swede, lettuce, and small quantities of fruit such as apple, pear, blueberries etc. No onion or potato. I use a wide variety so that the mix doesn't contain too much of any one thing. I add roughly a couple of dessertspoonful's to the food each meal.
