On a baking tray mix peppers, onion, chicken, seasoning and salt. Grill for 15 mins at the top of the oven.
Meanwhile, fold an edge of a tortilla over and then roll from one side of the flat edge to the other, creating a cone shape. Hold this in place with a cocktail stick and repeat with the other tortillas. Brush with oil and place on a baking tray.
Set the oven to bake (200°C/400°F) and move the fajita mix to the bottom to finish cooking, then cook the tortillas for around 10 minutes until they've crisped up and are nicely brown.
Fill the cones with the fajita mix then spoon the guacamole on top and a little sour cream.