This is an opportunity to have that quality time we hear so much about but often don't have time to pursue. Teach good table manners at home, and miraculously, your children will use good manners in public. If you wouldn't think it funny to have your child display his mouthful of food to your hosts at a dinner party, I suggest not letting him get away with it at home. Relax your attitude about food. The more focus and attention you place on eating habits, the more of a battleground food will become.
Kids can thrive eating the same foods over and over and avoiding anything new and different.
When healthy options are all that's available, kids will eat healthy food. Mealtime can be enjoyable when you serve the food, then simply take the time to enjoy it, without monitoring every one else's eating habits. Encourage your children to become involved in the meal planning and preparation. It will motivate them to eat what's served, and it will teach them valuable skills that will enrich their lives. You will probably be pleased to see that they actually enjoy helping in the kitchen.