I used the 3% of current body weight. So at 40 pounds that's 1.2 pounds per day, divide that over 3 meals so .40 pounds per meal. I'll tell you what I fed because it worked for us:
Breakfast: Muscle meat (ground beef or turkey or chicken), oatmeal, tablespoon of greek yogurt, some raw veggies (he likes them). Fish oil and supplements and 2 ounces of organ meat.
Lunch: Same minus the supplements, oil, yogurt and organ meat.
Dinner: RMB - Chicken necks, turkey necks, yogurt, oatmeal or baked sweet potatoes and tablespoon of yogurt.
At 6 months we switched to 2 meals a day and mine was up to 2 lbs of meat/day. He gets a beef rib bone a couple of times a week, also will snack on sardines, apples, bananas. Raw eggs a few times a week are added to one meal as well.
I know a lot of raw feeders don't agree on the oats or veggies but it worked for us and he's 13 months now and is healthy and happy. You do what works for you and your dog.