Thaw frozen prawns fully in the fridge first. Check that the raw prawns are peeled and deveined, then pat them dry. Peel and thinly slice the garlic. Wash and finely chop the parsley, and cut the lemon half into wedges.

Put the olive oil, garlic and chilli in a wide frying pan over a medium-low heat. Warm gently for 3–4 minutes until the garlic is fragrant and just starting to turn pale gold. Do not let it darken.

Increase the heat to medium and add the prawns in a single layer. Cook for 3–5 minutes, turning halfway, until the flesh is opaque throughout and piping hot. Larger prawns may take longer; a clean probe should reach 75°C for 30 seconds. Cook in two batches if the pan is crowded.

Stir in the salt and parsley and remove from the heat. Toast the bread while the prawns cook.

Serve immediately in a heatproof serving dish, with the garlicky oil, one bread slice per person and lemon wedges. Warn everyone that the pan and oil are hot.