Dilute the gelatin (sheets or powder) into the cold water and whisk to get a thick, glue-like consistency.
Place the cheese in a heatproof bowl and either microwave for a few seconds or place it in a double boiler to melt. Give it a good whisk and ensure there are no clumps of cheese.
Add the egg yolk and quickly stir to incorporate it into the cheese. Make sure you do this quickly so the egg doesn't start to cook.
Microwave the gelatin mixture for around 10 seconds at a time (or again using the double boiler) to help the gelatin dissolve. Stir well.
Add the gelatin mixture to the cheese mixture and stir to incorporate well. If the cheese mixture has cooled, microwave it for 10-second intervals until it is warm again. You should now have a soft dough.
Grease two sheets of baking paper and add the dough in between.
Roll out with a rolling pin (a bottle or tall glass would also do) into a ¼-inch thick sheet.
Refrigerate for 30 minutes and cut into long strips.
Make your favorite keto pasta sauce, like my low carb marinara sauce while the pasta sets. Serve with a hot pasta sauce of your choice.