Place the potato in a saucepan and cover with plenty of cold water. Bring to the boil over high heat. Boil, uncovered, for 8 minutes or until potato is tender. Drain. Set aside for 5 minutes to cool.
Place the potato in a large bowl. Add the flour and egg, and stir until just combined. Season with salt and pepper.
Heat the oil in a large frying pan over medium-high heat. Spoon five tablespoonsful of the potato mixture around the edge of the pan, allowing room for spreading. Cook for 2 minutes each side or until golden. Transfer to a plate. Repeat, in 3 more batches, with remaining potato mixture, reheating the pan between batches.
Place avocado and lemon juice in a bowl and use a fork to mash until smooth.
Heat a frying pan over high heat. Add the chorizo and cook for 1 minute each side or until brown.
Place potato tortas on a serving platter. Top with a dollop of avocado and a slice of chorizo. Serve immediately.
Recipe courtesy of www.taste.com.au
Serving size 20