Using a cheesecloth or clean tea towel, squeeze the courgette until you remove as much moisture possible. It’s easier if you squeeze it out in small batches.
Preheat a barbecue or grill to medium-high. In a large bowl, mix together all the ingredients for the burger until well combined, season with salt and pepper to taste.
Divide the burger mix into 4, roll into a ball then flatten into a burger shape
Cook the burgers for 12-15 minutes, turning occasionally, until cooked through.
Meanwhile, combine the spicy crema ingredients together and brush on the cut side of the top of the burger buns
Toss the shredded red cabbage with the lime juice in a bowl and set
Slice the rolls in half and toast cut-side down on the barbecue, or place cut-side up under the grill, for 1 minute until lightly toasted
Put the burgers on the grilled bun bases and top each with the avocado, red cabbage, lettuce.