The herbs below are what might have been used in Anglo-Saxon East Anglia, but use whatever you might fancy. Try to use fresh, although dried is acceptable.
6 fresh cleaned trout
6 sprigs fresh rosemary, or 1-2 tablespoons dried
75g (3 oz) soft butter
18 fresh mint leaves or 2 teaspoons dried
Leaves from 6 sprigs fresh thyme or 2 teaspoons dried
6 fresh sage leaves or 1 scant teaspoon dried
1-2 teaspoons coarse sea salt
6-9 grinds black pepper
Put one sprig or generous shake of rosemary down the middle of each fish. Chop all the other herbs and seasonings and mash them into the soft butter. Use this to coat the fish generously on each side. Griddle, barbeque or grill it for 4-5 minutes on each side or till the skin is well browned and the flesh flaking off the bone. Baste now and then with the butter which runs off. Serve at once.
The grilled trout is a combination of elements from each of these recipes. The first documents trout as an Elizabethan England fish, which was prepared and served like other freshwater fish of the era. The trout was cooked in a manner similar to the second and third recipes.