Offering your child some food choices is a powerful technique for overcoming fussy eating whereas offering them an alternative at mealtimes is going to fuel their behaviour.
If children learn (and they’ll learn very quickly) that you will cave in and offer an alternative when they say they don’t like a meal, they’re going to, very soon, refuse to try the food you’ve made at all. They’ll always expect you to prepare something else for them.
When using this approach of not offering alternatives, it helps to ensure there’s at least one food item on the table that they like.