Remove spam from tin (follow instructions on can, make sure it comes out whole). Place on chopping board and slice into 8 equal sized wedges. I find this easiest by halving (2), halving those halves (4), then halving each of those (8).
Lay each wedge flat and very lightly spread with dijon mustard (not too much, just enough for the cheese to stick ~1/2tsp). Lay each slice of cheese on top and firmly press down so it sticks to the spam.
Combine flour in a bowl with baking powder, white pepper and salt. Making sure the cheese stays intact, carefully (but thoroughly) coat each fritter in flour.
At this point pour 3-4cups/750ml-1litre oil in a deep pan and heat it to 180C/356F.
Once all the fritters are coated in the flour pour in the COLD beer. Use a whisk to stir (don't over beat or the bubbles with burst, some small lumps are fine). If you go OTT with the beer and it's too thin just mix in a few pinches more flour, vice versa with the flour. Again, you want the batter as airy and cold as possible so don't beat the hell out of it. It should be somewhat thin, but thick enough to coat the back of a spoon.
Use a fork to lower the fritters into the batter, allow them to fully coat, then carefully transfer into the hot oil. Work in batches of 3-4. You want to work fairly quickly as you want the batter to be as cold and bubbly as possible.
Once the fritters are in the oil the temp will drop, so try and keep it at a steady 180C/356F (increase heat as needed). Allow them to fry for a couple of minutes, then flip and continue cooking until golden. Remove one by one and place on a wire rack with paper towels UNDERNEATH (don't place straight on paper towels or they'll go soggy). Repeat with second batch.