1) Heat the grill to high.
2) Char the poblano chillies under the grill to blacken the skins on all sides, about 7 to 8 minutes. Place them in a bowl, cover with cling film and let stand for 10 minutes.
3) Peel and seed the chillies, then slice.
4) Heat a skillet over medium-high heat. Add a drizzle of olive oil then a tortilla. Cover the tortilla with 50g of cheese and a quarter of the chillies. Fold the tortilla in half and cook for 2 minutes to crisp and char the tortilla evenly and melt cheese.
Remove and cut into wedges; repeat with the remaining ingredients.