I don't know if this applies here or not, but if you have a bulk store, here we have Nutters, and Bulk Barn. I believe the Bulk Barn has bonemeal, but
am not sure.
Hope it gives another idea.
I had a friend that made a stew type meal for her dog, froze it in meal size containers, and would take out 4 or 5 days at a time. They would thaw in the fridge, and if I had to feed the dog, I would dump the container in his dish, and then wash the container for the next time she did the cooking. I believe she made it, then cooked it in the oven, but I cannot ask her, as she has passed away. I do remember carrots, peas, meat, I think she added some rice, and maybe some yam/sweet potato., and of course made gravy from the meat drippings after.