Heat the oil in a frying pan, add the vegetables and fry for a few minutes until starting to brown.
Add the fajita seasoning and fry for 1 minute.
In a bowl, mix together the refried beans and passata and stir well.
Spread the tortillas out on a baking tray and pop into the oven for 3 minutes, just to crisp up a little. Be careful not to over-brown. Remove from the oven.
Lightly grease the bottom and sides of a 20cm springform tin or a circular ovenproof pan.
To assemble the pie, start by placing one of the tortillas in the bottom of the dish, spread a spoonful of the tomato mixture, top with a handful of beef, vegetables and a little cheese, place another tortilla on top and continue the process until you finish with the final tortilla on top.
Sprinkle over the remaining cheese and place in the oven for approximately 25 minutes until it’s piping hot and the cheese has formed a crusty surface.
Sprinkle with spring onions and serve with a green salad.