Yes, I did mean a wasteblock.
Once you have some experience you can use a chuck to great advantage.I would like to make a curved platter
Instead of a tenon you could us a recess of as little as 1/8" deep and thereby have the foot completed.Once you have some experience you can use a chuck to great advantage.
Mount the blank on a worm screw. Turn the underside of the platter and a tenon 1/4” or less tall
Use the tenon mount in the chuck and turn the top side of the plater.
This is a much used method and wastes little wood