Try dropping them on the counter where you put the groceries instead. As long as there are no groceries to put away, they should begin preparing a meal.

Also, when they do this praise them and they will do it on their own more often.

If they do this put them on the table. Praise them often, but not to much. (If you do they will run away and say "STOP NAGGING!")

YES I always laugh when they do that.