Cut each fillet into approx 3 strips each. Spread mustard on each chicken piece on one side. Add a small amount of oil to a frying pan and lay the fillets with the mustard side down. Brush the tops of each fillet with mustard. Don't worry if it sticks a little or goes a little crusty..this adds to it. If I am just making a quick meal for the family I chop up the chicken, stir fry it and just add a few spoonfuls of mustard directly to the pan.
When the chicken has been browned on both sides, add chicken stock. I didn't put in an amount because it depends on how much gravy you would like. For two fillets with small amount of gravy it is 1 cup.
Simmer the chicken slowly with a lid on. Close to serving time, add the evaporated skim milk. DO NOT BOIL. Heat through gently and then thicken with cornflour that has been made into a paste with water.
For a special meal I serve this on a moulded rice pile with green beans and honeyed chicken as a side. Drizzle the mustard gravy over the chicken and top with roasted slivered almonds. For a quick family meal it is just served on a bed of rice.