I felt we had some distinct phases of distrust of foods when my DS was younger. It seemed with developmental leaps in other areas (such as language, motor skills etc) there came another phase of testing the world around him in all sorts of aspects including eating. He would question foods I knew he liked as though he'd never seen them before.
One thing which helped here was to "taste test" each food - I joked saying I was testing for poison like a jester testing the King's meal! Once I had take a tiny bit of each item from his plate, eaten it and said "mmm, that's good, that's okay to eat" he'd happily dig in. Seemed a bit odd but it worked and was just a phase. It also helped to show him my food was identical to his, I could see him eyeing my plate to check so I would point out all hte same things were there.
Another thing you might consider is that your LO is just not so hungry at dinner time. Often LOs take in more calories in the earlier hours, morning and early afternoon rather than evening. it can appear they are picky eaters but it is just that they have taken on board enough calories and so can be picky or hold out for a certain thing. Moving dinner earlier may help. We used to eat as early as 4 or 4.30pm, even now we eat at 5pm which I still think is early.
Otherwise I would continue to keep offering the same meals and foods, this is a time when you can end up limiting his diet if you start to cut back on the variety for fear of him not eating it. Make smaller portions or offer smaller portions to reduce waste but do keep exposing him to those foods. Having a "real" dislike of a food is quite different to having a phase of not eating a food.
If he likes fries (I'm in the UK I call them chips
) how about trying some oven baked fries made of white potato, sweet potato, carrot, parsnip, turnip, swede, celeriac...you don't have to try all at once of course. Mine loves "chips" he knows I make all different types of chips and likes them all.
Mine was also not keen on meat, I found certain things he would take more readily - slow cooked lamb shank (very soft), slow cooked pulled pork (again soft), sausages (we get the best quality possible). Maybe try some eggs? Fish? bean burgers/fritters and lentil burgers were eaten often here - I made a batch all cooked then after cooling froze them with baking parchment between so they didn't stick together then if I knew we were having a meat he was unlikely to eat I could defrost a few for DS and know he was getting some protein. I also (for a time) served an egg every breakfast so I knew he had at least one portion of protein in the day, it really helped to reduce my concern and he took it happily and with appetite in the morning where as would refuse egg later in the day. Actually serving foods (you know he likes but he is refusing later in the day) at breakfast can really help overall. If it's veggies you can save a portion from cooking dinner the night before and offer at breakfast time, he might just surprise you and eat them all.