The butcher block is a good idea. I ran this through my head several times. A mix of hardwoods cut in 1" wide by 2" thick strips. Run them though a joiner on the 2" side and then use outdoor epoxy, glue them together and clamp. When it all sets up, have the entire slab planed to finish. Then cut out the circle and radius the edges. finish sand and then seal with mineral oil. You have the cover so it should last a long time between added oil treatments. May cost more than $50. But would that set off the gray kettle and look way cool. You'd have a one of a kind............
