We have been through this 4 times now.
1. Accept you may not be able to get anything down them. Our last girl was always difficult with food and we resorted to steak, chicken breast, tinned tuna in desperation, anything we could get down her, after amp.
2. Hold your nerve. And buy non slip rugs. And get good pain relief (the patches are the best thing ever). Good, spaced pain relief makes a huge difference to recovery.
3. We had Meggie on raw before amp and chemo. I took her off raw during chemo and discovered freeze dried raw. It is the only thing that saved us from her (being a complete cow) starving herself to death. She has always been a cow with food.
Rather than home cooked where it is difficult to balance the essential minerals and vitamins we looked at a freeze dried raw (orijen and a locally produced one) as it is so low carb and you need to get so little down them to maintain weight and condition.
You might want to do some research into golden paste, turmeric paste. It may not be for you but the clinical research is quite promising.
Good luck. Our girl is over a year post amp and going strong! We caught it early, did amp and chemo as fast as possible. This was as soon as her stitches were out...