Cut the asparagus into diagonal chunks and place in
a bowl. Pour over boiling water and leave to stand
for 2 minutes then drain.
Slice the lamb thinly
against the grain. Heat the oil and stir-fry the
lamb until lightly colored. Add the salt, pepper
and garlic and stir-fry for 5 minutes.
Add the
asparagus, stock and tomato, bring to the boil,
cover and simmer for 2 minutes.
Mix the corn-flour,
water and soy sauce to a paste, stir it into the pan
and simmer, stirring, until the sauce clears and
thickens.