Heat the oven to 200C (180C fan)/390F/gas 6.
Put the feta on a lined baking tray, drizzle with the olive oil, then scatter over the oregano and/or thyme and chilli flakes, and bake for 25 minutes.
Meanwhile, mix the pineapple, onion, chilli, mint and lime zest, then add the lime juice and salt a little at a time, tasting as you go.
You may need all or just one of the limes, depending on how juicy they are.
Warm the tortillas in a hot pan for 30 seconds per side, or according to the packet instructions.
Pile the lettuce, pineapple salsa and hot, broken-up feta into the tortillas, and eat immediately.
