Just thinking in another direction here, how are you doing with soups?
It's easy to 'hide' the meat if you use minced meat, veggies and a stick blender, and it still holds all the nutrients you'd get from traditional food.
It doesn't take a lot of work and it's easy to freeze in portions and just reheat a bowl in the microwave, so you can even eat it on days your legs don't play fair.
I do make soups quite often, and usually enjoy them and sometimes they are made with a meat base - usually chicken stock with no actual meat in it. Not sure if that is sufficiently high in protein to be helpful. I do make a lot of ragout with minced beef and, since it has lots of tomato in it, I think I can cope with that; I could increase the stock volume and decrease the meat a bit, which would make it more palatable.
My soups used to contain lots of pulses but they have too much carbs to be useful now. Beans and soya milk is where Neil gets his protein usually although he is hitting the sardines in spring water just now, to try to get his Crohn's back under control.
It sounds as though a totally liquid diet isn't going be right for me. Perhaps I should investigate tofu - not that we have much of a range available here - mostly the soft kind which is not so easy to cook with. I can still eat cheese (usually) and still can eat the wholemeal bread that we make, but again, can't live on that - one slice a day is about the maximum carbs for me.
Will see if Neil can get any of the whiter meats in minced form rather than cooking with beef all the time. Those would be more easily hidden in a soup. He hasn't been able to get any other kind of mince for me so far but I'll ask him to try again - once he is fit to go shopping again.