Heat the oil in a skillet large enough to fit both salmon fillets. Add the garlic, followed by the sugar and fry for a minute until the sugar melts. Add the onions and cook them for further 2 minutes until softened a little. Pour in the oyster sauce and water and stir in.
Turn up the heat until the sauce bubbles and place the salmon in the skillet skinned side up. Cook for about 5 minutes until the bottom of the fillets turns lighter colour a third way up. Add more water if the sauce boils off and threatens to burn.
Turn the salmon over carefully, spoon the sauce over the top and cook for further 3-5 minutes, depending on the thickness. You can check if it’s cooked to your liking by gently prodding a fillet with a knife in the middle to see if it flakes and is opaque – or almost – inside.
Serve with the sauce spooned over the fillets, with green vegetables and rice or new potatoes.
