Preheat the oven to 220 C, Fan 200, Gas 7. Line two baking sheets with baking paper.
Put the courgette into a bowl with a good measure of oil, half the paprika or chipotle and half the cumin. Season with salt and pepper and mix until well coated.
Spread out evenly in a single layer on one of the prepared baking sheets and roast for about 10 minutes. Sprinkle over the garlic and cook for a further 5 minutes until the courgettes are golden in places and tender throughout.
Mix a good measure of oil in a small bowl with the remaining spices. Spread the broken tortillas on the second baking sheet then pour over the spiced oil and turn through to coat evenly.
Bake in the oven for 5-8 minutes until toasted, then remove from the oven.
Scatter half the toasted tortillas over a large serving dish. Top with the cooked courgettes and the avocado.
Distribute the feta, coriander, remaining tortillas and the sliced chilli ( if using) on top. Serve with wedges of lime to squeeze at the table.