Use half the softened butter to grease a large roasting tin and lay the slices of potatoes on the top. Scatter over the garlic, onions, rosemary sprigs and bacon or pancetta pieces, season with a little salt and ground black pepper.

Cook in a pre-heated oven at 200°C (400°F) mark 6 for 20 minutes, until just cooked and lightly golden around the edges.

Arrange the trout fillets skin side down on top of the potatoes and smear the remaining butter on the fish. Scatter over the shredded almonds and season. Return to the oven to cook for a further 5-6 minutes.

Meanwhile, mix together the horseradish cream and lemon juice into the crème fraiche, season well. Serve the potatoes and fish with a spoon of cream to accompany