hard cheddar BrE informal
tough cheddar
stiff cheddar AusE informal

The cheese of the moon ranges from almost liquid brie to rock hard cheddar.

A sweet digestif made from local cider, cidre de glace, was on the house and combined well with the hard cheddar, runny goat, funky sheep-cow and raw milk Camembert.

That if they cannot get funding because companies aren't interested in their brand of research it's toodlepip to English depts and it's just hard cheddar and no loss to British academia?

it would be tough cheddar if she couldn't find a way to grab herself a part of the action.