Mexican is probably my FAVOURITE type of food. There's something about chips, guac, and burritos that make the world go round.
Lately my favourite type of fajita/taco filling are portobello mushrooms - they're such a substantial topping that add so much flavour and texture.
To make the portobello mushroom I remove the stem and then place them on a glass baking dish. I add a little salt and pepper and then bake them for 20 minutes, flipping them half way. You don't need oil! I find it works best if I start them stem-side up to start.
While the mushrooms are baking I make a simple guacamole, and heat up the corn and red peppers on the stove (again, I don't add oil for this. I just add a splash of water when they start sticking to the bottom. For this I actually let them stick and burn a little bit before adding the water, because I find it add so much flavour).