Involving your child in the meal planning and allowing them to make suggestions for family mealtimes (perhaps allow them to choose the meal once a week) can help them feel empowered and that they have some control over their own food choices as well as relieving some stress for them as they are able to occasionally eat their safe and preferred foods.
You may have to think about what else you need to prepare to go with the suggested meal so that everyone around the table has access to food they will eat and so that you’re offering a balanced meal, but the bare bones of the meal can be your child’s choice.
Knowing that your child may always choose the same meal if asked for a suggestion or that the meal they request might not be the healthiest of choices, you might prefer to ask them to make a choice from two options that you’re happy with but that you know they like. They still have some decision-making power and control over their food choices but with your guidance.