Preheat oven to 220°C/200°C fan forced.

Cook potato in a large saucepan of boiling water for 3-5 minutes or until just tender. Drain. Whisk eggs and milk together in a jug. Season with pepper

Heat oil in a 5cm-deep, 22cm (base measurement) non-stick, ovenproof frying pan over medium-high heat. Add onion, sliced chorizo and garlic and cook, stirring, for 5 minutes or until onion softens and chorizo is crisp. Add paprika and cook, stirring, for 1 minute or until fragrant

Add potato and season with salt and pepper. Stir gently to combine. Lightly press potato mixture into pan to form a slightly compact, flat top. Reduce heat to low. Pour egg mixture over potato mixture. Gently shake pan to allow egg mixture to evenly spread in pan. Cook, without stirring, for 2-3 minutes or until base and edges start to set. Transfer to oven. Cook for 8-10 minutes or until top is golden and egg is set

Meanwhile, cook the finely diced chorizo in a non-stick frying pan for 3-5 minutes or until crisp

Stand tortilla in pan for 5 minutes before inverting onto a serving plate. Serve scattered with chives and chorizo crumb