Cut the tofu into bite-sized pieces.
Pat dry the tofu and grill it on a pan over low heat until golden brown on both sides.
Finely chop the onion and bell pepper.
Drain the oil from the canned tuna.
Add the chopped onion, bell pepper, and tuna to a pan, season lightly with salt and pepper, and stir-fry.
Layer the grilled tofu in an oven-safe dish and top with the stir-fried mixture.
Pour tomato sauce over, then sprinkle pizza cheese on top.
Bake in a preheated oven at 180°C (356°F) for 10 minutes.
Finish by sprinkling parsley flakes.