I would just give a hunk of the chicken. If he does nothing but sniff and fiddle with it it's ok, he will be learning many things and becoming familiar with this new 'stuff', familiarity helps when it comes to trying new foods. I had a Kenyan friend many years ago who told me they give their kids chicken bones as teethers - but I don't think this would be advised in the UK for fear of the bone splintering.
Lentil burgers. I used canned lentils as I am lazy
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Drain and rinse in fresh water, take off excess water with absorbent kitchen paper. Or pre-cook dried lentils as per pack instructions and drain. Then just stir in an egg and some flour to bind the lentils together, add any seasoning you think LO would like or which you have already tried him with (I'd avoid salt at this age but garlic, tumeric, paprika, tomato puree, mixed herbs, anything like that to give some flavour), give it all a good stir and form into patties, fry. If the mixture is too slack to form into patties just cook like fritters (ie blobs of mixture) or if it is really thin cook like American pancakes (a dollop of the mixture into a hot pan and flip it over).
You can make these smoother by mashing or whizzing the lentils, I sometimes did a mix of some mashed some whole.
You can add any left over veg from the day before too. Or you can finely chop onion and mushrooms and fry them off before adding to the mix.
You can also fill (or half fill) a mini muffin tray and cook them like mini meat loaves in the oven.
TBH I used to make it up every time, you just need to bind them together really.
If lentils don't go down well it's worth trying a range of beans. For instance mine really didn't like red kidney beans or butter beans but loved all others, it must have been a taste/texture thing because once they are cooked as patties I don't think he could tell visually they were any different.