I'm 4 weeks out so I'm no expert but I'm also not a big/good cook. I've cooked twice since post-op. I started puree/soft foods 2 weeks ago and this is what I do...
For breakfast and/or lunch, I eat yogurt or have a protein shake. My nutritionist said I can have turkey bacon so sometimes I throw some in the microwave and have that.
For dinner: I've been eating canned salmon (not big on tuna) and canned chicken. They last a pretty long time and there are some really simple recipes for them. I don't consider that cooking because mostly I saute them with frozen onion and peppers, season it and I'm done in 10 mins. If I want more flair, I'll add a small amount of teriyaki sauce or oriental sauce.
As far as fast food, I've also had rotisserie chicken from the Peruvian restaurant by my house. It went down better than the canned meat! Right now for the most part I just eat meat so it's pretty easy to track. I have a digital scale and I just measure out 3-4 oz.
The 2 meals I cooked were 2 different types of chili. Both of which only had like 5 ingredients. I had leftovers for a few days.
I haven't been to a restaurant yet but I like all the advice that BigSue gave on this. I'll def keep them in mind!