Add the chunked pork and toss to combine to heat up pork up slightly, a minute or two. While the apples are cooking toast up the English muffins until they are golden, remove from the toaster and spread lightly with butter.
To assemble sandwiches, divide the sliced pork between the 8 toasted muffins. Top each one with some of the apple mixture, then top that with a slice of the cheddar cheese. Transfer to the oven or broiler for a few minutes to melt the cheese.
While the cheese is melting, combine the remaining cider vinegar with the honey in the bottom of a salad bowl. Add EVOO in a slow steady stream, whisking to combine. Season with some salt and pepper then add the watercress and toss to coat.
Serve the sammies with the sweet apple dressed greens alongside.