Saute onion and garlic until onion is golden and translucent
Add mince and fry off
Add stock cube with half a cup of water plus the cornflour slurry
Simmer and reduce to create a fairly dry mince mix
Let the mince cool
When ready to make, heat the pie maker, cut the puff pastry into 4 squares
Pop a square into each pie maker hole, spoon in a quarter of the mince and fold the pastry corners over each other to form a lid
Cook 10 minutes or so, until the pastry is golden
Notes
Don't make the mince gravy too runny as it'll burst out of the pie when you bite into it.You can use cold mince but you'll need to adjust the cooking time. Perhaps 5 minutes longer, to make sure the centre filling is hot.