Wrap the tortillas loosely in foil and place on a baking sheet. Warm through in a preheated oven, 220°C (450°F), Gas Mark 8, for 3–5 minutes to soften.
Place the cheeses in a bowl and mix together, then season. Divide the mixture among the tortillas, spreading it down the centre of each one, then roll up tightly and place in a lightly greased baking tray, seam-side down. Brush over the oil and place in the oven for 5–10 minutes until golden and crisp.
Arrange the lettuce, radish and tomato on a serving dish. Squeeze over the lime juice to taste and season with a little salt. Top with the cheese tortillas and serve.