Place yeast, sugar and water into Thermomix bowl and warm 2 min/37ºC/speed 2.
Add pink salt and flour and blend 6 sec/speed 6. Knead 3 min/Interval.
Turn out onto floured Silpat mat and prove until doubled.
Preheat oven to 220ºC and line a baking tray with paper.
Divide dough into 4 equal pieces.
Roll each piece like a sausage and then flatten so that you have a long piece of flat dough.
Place chorizo and cheese into Thermomix bowl and blend 6 sec/speed 6. Using damp hands, form small balls with the sausage mixture.
Place a ball on one end of the rolled dough length. Fold over to form a little parcel, cut to separate from the long piece of dough and pinch all edges together to seal. Set aside. Repeat with all dough and sausage mixture.
Bring water to the boil and add baking soda, stirring to dissolve.
Boil each little pretzel for around 30 seconds and remove with a slotted spoon. Place onto prepared tray, brush with egg wash and sprinkle with a few (very few) grains of salt.
Bake for 10-15 minutes until golden brown and centres have melted.
Eat immediately with cheese sauce or homemade tomato sauce.