A Vit a Mix is a heavy duty blender that will turn a pice of twoXfour into sawdust! The motor is so powerful that it will heat the food you puree. A regular blender will probably do, but you might wear it out. Of course a regular blender will not heat the food, but that why we have stoves.
Here is a recipe for you:
1.5 cups milk
.5 cup cream
2 nuked medium size potatoes
handful of cheddar, shredded
.25 of a small onion (or use a bit of onion powder)
rosemary to taste
salt to taste
Pepper to taste
2 slices of crisp bacon, crumbled
In the order listed above, place ingredients in blender and blend until preferred consistency is met. Thin with milk or cream or thicken with additional potato, if necessary. You can vary this recipe by adding broccoli, spinach or any other cooked vegetable. Depending on how compromised his swallowing is, you can also add chopped meats, such as chicken or ham. I would add a couple of dollops of butter for additional calories.
Good luck.