I resorted to cooking for my dog when he developed hypothyroidism and zinc deficiency when on a soy and corn veterinary diet.
There were so few foods that he didn't react to (lymphocytic/plasmacytic ibd) that I wanted to ensure that he was eating a nutritionally complete diet using the few foods he could eat.
Eventually I came across Raw Fed and Nerdy and, although he couldn't eat raw due to his compromised immune system, I used the free service they provide which gives you the nutrient requirements based on your dog's weight and NRC guidelines
https://rawfedandnerdy.com/adult-dogs-nutrient-requirements.
Armed with that information I then joined Cronometer (free) and entered his target values and saved them - it's a bit time consuming but you only need do this once. You can then enter each day's diet and see if you are meeting targets for nutrition and what needs tweaking.
If the food you are feeding is not on the database you can look up the nutritional info on the internet and enter it yourself.
You can't use minces with bone as you should not cook it, it needs to be meat/organs without bone. I added seaweed calcium, I used Animal Essentials and Lunderland.
I did not use the following services but they could be useful if you are short on time.
Charley, The Raw Vet, offers a service where she will analyse what you are feeding "Check My Diet".
Savannah, Raw Fed and Nerdy, will formulate a diet for your dog.
Cat Lane, The Possible Canine, a canine nutritionist - you will find her on face book, will also formulate a diet based on your dog's requirements.
I hope something in this information might be useful to you, Planete.
ETA. Linda Case's book, Canine and Feline Nutrition, seems to be well recommended but I thought it might be over my head.