You can make a lot of your own "baby" foods at home. Cook until tender and either mash them up, or blend them until smooth. Add some seasonings (salt, pepper, herbs, spices), some butter or margarine, and some broth or milk/soymilk to make them a little more interesting.
Another thing you could do is drink some Ensure or Boost. Making your own smoothies is good, too. Fresh or frozen fruit, concentrated fruit juice, milk/soymilk, tofu, yogurt/soy yogurt, maple syrup, blackstrap molasses, ground flaxseeds, peanut butter, avocados, flaxseed oil, can all be put into smoothies. You can mix and match and make some very tasty combinations and they're easy on the stomach.