My three year old demolishes veggies but does have preferences which can be gamed with combo eating. The "cut them smaller and mix with other stuff" strategy is a winner. Another is stronger sauces eg. balsamic or mustard in salads. Or mix with strong interesting components like nuts, cheese, pickled gherkins or less spicy preserved cabbage/kimchi. My daughter loves vinegar so much she often drinks the left-over salad dressing!