It isn't your job to 'get' a child to eat.
Your job is to provide the food you think constitutes a balanced diet and it is his job to select from that what he would like to eat.
Any pressure, encouragement, reward, sanction or cajoling is likely to result in him eating less.
Put the food out, preferably in serving bowls on the table with everyone eating together, let everyone serve themselves and have a nice social occasion in which you talk about everything but food. Don't praise him for eating, offer him tastes or comment on how much he has had. Just let him do his job.
Handling food can help so try to encourage him to help prepare food of everyone else, even if he isn't going to eat it. Being more used to the texture and the smell of a food makes it easier to try it when the time comes.
No matter how little he has eaten, just ask him if he has finished and take his plate away. Don't withhold fruit/yoghurt/dessert. That just teaches children that savoury food is unpleasant and must be tolerated in order to be rewarded with sweet food.
Keep every bit of the stress this causes you completely to yourself - I really do know how hard that is - and keep smiling and chatting as if you don't have a care in the world.