I've been on liquids and purees since I left the hospital, in two days I'll officially move on to the soft foods stage. When I had my sleeve done 3 years ago I remember cooking whatever meat or fish I had in a broth (either chicken or beef or vegetable - Better than Bouillon is great for this). It's not sous-vide as that takes ages - I wasn't hard boiling it, but since it was so little meat it cooked pretty quickly. Meats tend to be more tender this way and can be easier to eat at first if other methods (oven baking, grilling, etc) are not as successful. Poaching eggs the traditional way (right in the water) is another option.
Personally I love Shelly's egg bites recipes on theworldaccordingtoeggface.com - I've tried quite a few, and am already planning which ones I'll eat this week. I've done the ricotta bake before but it's hard to find ricotta in Japan so I'll have to see if I can source some tomorrow. She also has a lot of other recipe ideas for different stages, it's worth taking a look if you haven't already: http://theworldaccordingtoeggface.blogspot.com/2007/08/pureed-foods.html