Cheese and BEETROOT not tomato.
The cheese should be solid blocks of cheddar/mousetrap.
Beetroot chopped in clumps from a whole one but the sliced variety from a jar or a tin is ok but only because it's better than no beetroot. The vinegar may even help to avoid serious indigestion from swallowing the cheese after the merest hint of an introduction to the effects of mastication. :)
And the longer the cheese has been (unwrapped) in the fridge - measured in months - the better. By today's standards some months past the Sell-by Date. Sheesh when I were a wee lad there was no such thing as sell-by dates. Today's yoof need them? Really? (Shakes head in mock sympathy)