Heat
oil in a pan. Add garlic and stir briefly. Add at
third of beef. Stir-fry 1 minute until it changes
color. Remove and repeat with remaining slices.
Return beef to pan. Add soy sauce and sherry, and
cook for 1 minute. Pour in 1/2 cup (125ml) stock.
Blend cornstarch with oyster sauce, remaining stock,
soy sauce, sugar and salt. Stir in to thicken. Serve
at once.