Salmon roe is available at most seafood stores and is sold either in small jars or by weight.
4 rainbow trout, cleaned and scaled
1 large lime or lemon, finely sliced
12 lemon thyme sprigs
olive oil, for brushing
Salmon roe butter
50 g (1¾ oz) butter, softened
1 teaspoon lime or lemon juice
½ teaspoon chopped tarragon
½ teaspoon snipped chives
1 tablespoon salmon roe
1. Preheat a barbecue flat plate to medium. Rinse each trout in cold water and pat dry inside and out with paper towels. Fill each trout cavity with slices of lime or lemon, put 3 sprigs of lemon thyme in each and season with salt and freshly ground pepper.
2. Lightly brush the hotplate and the trout with oil. Barbecue the trout for about 4 minutes, then turn and grill for a further 4 minutes, or until cooked through.
3. While the trout are cooking, make the salmon roe butter. In a bowl, beat the butter until smooth and stir in the lime or lemon juice, tarragon and chives. Gently fold in the salmon roe and season with freshly ground pepper.
4. Arrange the trout on four serving plates. Put a generous dollop of the salmon roe butter on each trout and serve immediately.