Separate the lean and fat. Dice each into pea-sized pieces. There should be about 350g of lean and 150g of fat after trimming.

Make the candied pork fat: blanch the pork fat for ~2 min, rinse and let it drain for a minute or two. Lay in a bowl with alternating layers of pork fat and sugar. Cover, leave in the fridge overnight.

Mix the lean with the marinade. Cover, fridge overnight. The 3g of nitrites powder can be swapped for 1.25g (or about ¼ tsp), and optionally add in 0.25g ascorbic acid (vitamin C). These numbers are closer to modern Western sausage preservation quantities.

Next day, cut out ~6ft of your casing and soak in warm water for 20 minutes.

Rinse the sugar off the pork fat, drain for a minute or two. Combine the lean with the fat, together with the 75g of water. Mix very well, ~3-5 minutes.

Scrunch your casing up the bottom of a funnel, leaving ~2 inches of casing remaining at the end. Tie an overhand knot at the end of the casing.

Stuff the filling through the funnel with the wide end of a chopstick. Once you stuff it with ~2 inches remaining at the end of it, tie another overhand knot to close it up.

Using two toothpicks or needles, puncture the sausage every half inch or so down the whole casing. Turn 90 degrees, and repeat until you made little holes throughout the sausage and on 4 of its "sides".

Cut out four ~8 inch sections of baker's twine, tie it in a loop. Separate the sausage into individual Lap Cheongs by laying the loop of twine under the sausage, looping it through the loop, and tightening.

Dry the sausage. Give the sausages a quick rinse, pat them dry and put in the oven at 50C for 24 hours. Then hang in a cool, dry, sunny place for ~3 days.