Antium (modern-day Anzio) lies 50km south of Rome on the Tyrrhenian Sea.
125g walnuts, finely chopped 90g salted butter, melted, plus extra 100g melted 55g capers, finely chopped, plus extra to serve 50ml extra virgin olive oil 2 tbs dry white wine 1 tbs walnut oil 1 small garlic clove, crushed 12 jumbo or extra-large scampi (in shells), split lengthwise, deveined Baby cress (optional) and lemon halves, to serve
Preheat a barbecue or chargrill pan to high heat.
To make the dressing, combine walnuts, butter, capers, olive oil, wine, walnut oil and garlic in a small bowl.
Brush scampi with extra melted butter and season with salt flakes. In batches, grill scampi, cut-side down, for 3 minutes, then turn and cook for a further 1 minute or until just cooked through. Serve immediately topped with walnut sauce, and scattered with baby cress, if using, with lemon halves.