On the site that I order Ben's food from, I've come across what I think is a very nice looking tinned food. I put "toppers" on Ben's food, often, but these would offer a little more variety. Here are the ingredients of the ones I'd be most likely to give him:
Turkey with Potatoes, Vegetables and Pears:
Fresh turkey muscle meat, turkey hearts, carrots, potatoes (10%), pear,
broccoli, millet (3%), whey, wheat germ oil, linseed, parsley,
basil, spirulina algae, organic eggshells, drinking water (meat 50%).
gluten-free
Venison with Pumpkin, Cowberries and Spelt:
Deer muscle meat, pumpkin, zucchini, carrots, beetroot, root celery,
spelt flakes, oat flakes, low-fat yogurt, wheat germ oil, cowberries,
chives, Chlorella algae, organic eggshells, sesame, drinking water
(meat 45 %).
Rabbit with Wholemeal Pasta, Wheat Bran and Wood Garlic:
Rabbit heart, lungs and liver, rabbit muscle meat, whole meal pasta
(10%), tomatoes, zucchini, black salsify, rape oil, fresh wild garlic,
fresh chives, linseed, mineral soil (healing earth), organic eggshells,
Andean salt, drinking water (meat 50%).
Bear in mind this would be a once or twice-weekly thing, not his daily diet. Any reasons not to feed this, from you nutrition gurus who are far more knowledgeable than I? He has no allergies that I've ever been able to discern except that raw celery makes him vomit. (Cooked and pureed does not so I think it must be that the stringiness makes him gag.)