Make the bravas sauce: Heat the olive oil in a small saucepan. Stir in the flour and cook over a low heat for 1 minute. Add the paprikas mix through then add the passata and water gradually, to avoid lumps. Add in the vinegar, sugar and salt and mix until dissolved, then let it come to a simmer. Remove from the heat once thickened.
Prepare the potatoes: Wash and peel the potatoes. Chop into rough 3 centimetre chunks. Rinse under cold water and pat dry.
Heat the oil to 140C. Carefully add half of the potatoes to the hot oil and cook for 6-8 minutes until soft but still pale. Drain on kitchen towel while you repeat with the second batch. Spread them out to cool and heat the oil up to 180C. Once the potatoes have rested for 10 minutes, cook them at the higher temperature until they are golden brown and crisp. Do this in batches if necessary. Drain on kitchen paper.
To serve: Transfer the hot potatoes to a serving dish and toss with 1 teaspoon of sea salt flakes. Spoon the bravas sauce on top then drizzle over the aioli and sprinkle with chives. Serve immediately.