Daycare already served lunch
Read the note from daycare if there is one. Match dinner to what is left in the day, not to a perfect plate.

Home is the familiar place
Tell daycare the allergy list in writing, and name one food your child eats. Home can then be the familiar place.
A full daycare lunch means a short dinner is allowed. A skipped daycare lunch means the familiar food at home matters more.
The written list
Milk, egg, wheat, peanut, tree nuts, soy, sesame, fish: write the ones that apply. “He’s picky” is not the allergy list.
Vegetarian is a separate sentence: no egg, meat, or fish.
Do not double the challenge
If daycare already offered something new, home does not have to offer another new food the same day.
The familiar food at dinner is the soft landing.
A sentence you can say
“Daycare fed you. Home is the food you know.”