Heat the vegetable oil or bacon fat in a heavy-based frying pan over medium–high heat until it shimmers but doesn't smoke.
In a medium bowl, stir together the cornmeal and salt until evenly combined.
Carefully pour the boiling water into the cornmeal mixture, stirring continuously until a thick, sticky dough forms.
If the mixture seems too dry, add another tablespoon of hot water; if it's too wet, sprinkle over a little more cornmeal.
With clean hands, divide the dough into portions of roughly 4 level tablespoons (about 60ml) each and shape into patties about 1cm thick.
Place the patties in the hot pan without overcrowding and fry for 3–5 minutes on each side, until golden-brown and crisp.
Transfer the cooked cornbread to a plate lined with kitchen roll to drain any excess fat.
Serve immediately, while still warm and crisp.