Trim tenderloin of excess lining, pat dry and rub with olive oil.
In a bowl mix together all the herbs, spices and brown sugar.
Run onto the pork making sure the entire surface has been coated.
Heat skillet or oven-safe pot on a high flame. Add soyabean oil. Note: a high heat is needed for a good sear but ensure the oil is not burning. Monitor the flame.
Place the pork and sear all sides until brown.
Bake in the oven for 12-15 minutes. Note: I have always found that 12 minutes to be perfect for the pork but if you wish to reassure yourself, a temperature of 140-145 degrees on your thermometer will work as well.
Allow to rest for 5 minutes.
Using the same pan from the pork place on medium flame and add the onion, garlic and mushrooms. Note: If there is an extra excess of residue from the pork remove a little. After all, we want the flavour but not burnt pieces.
Next, include the milk and stir removing the brown bits from the pan. Season with salt and black pepper. Allow the sauce to come to a simmer and then add parsley and take off the fire.
Accompany the pork with vegetables or rice and drape the sauce over the pork.