Uncle Aitchy's Baked Trout

Uncle Aitchy is a bit of a classic kiwi bloke. The strong, silent type. Accomplished digger driver. Always has a classic line at the most unexpected times. And in good hunter gatherer style, is a keen fly-fisherman.
Over the years the hunter has often provided Uncle Aitchy with a feed of venison, or duck (or what ever else it was that met it's end over the weekend...), so every now and then we are lucky recipients of a beautiful, fresh Alpine Trout.

This is Aitchy's recipe and a fun way to serve trout, especially to people who think they don't like it.
Note that in this case I used a side of trout, but you can just as easily use a whole trout and just stuff the filling in the gut cavity.
This is a blokes recipe so it's pretty hard to mess this one up.

Ingredients:

A side of Trout
1-2 Tomatoes
1 small red onion or large spring onion
1/2 Red Pepper (Capsicum)
2 mushrooms (any type)
1 Lemon
Olive Oil

Method:
Finely dice the tomatoes, onion, capsicum, and mushrooms.
Pile evenly onto the flesh of the fish. Chuck a few of slices of lemon over the top. Pour on a good glug of quality olive oil.
Bake at 180 deg Celsius until cooked through (20+ mins).
Serve with a fresh green salad.