Peel and boil sweet potatoes, Chop and saute onions, mushrooms and zucchini. Drain sweet potatoes when cooked, mash then add soy milk.
Add onions, mushrooms and zucchini to sweet potatoes, mix through with teaspoon of mustard/tahini.
Grease ramekins, open each tin of tuna/salmon and add to ramekin, stir through 1 teaspoon of mixed veggies of choice (if using plain tuna/salmon). Top with sweet potato mix.
Place 1/2 slice of cheese substitute on top, bake in moderate oven (180 degrees C) for 20 mins. Wait until outside of ramekin is cooled before serving