Pre-heat the oven to 200°C, 400°F, Gas Mark 6. Place the potato cubes onto a non-stick baking sheet and pour over 1 tbs of the oil. Sprinkle with the Rosemary and toss to coat the potatoes. Bake in the oven for 45 minutes.
Meanwhile In a large pan over a medium head add the remaining oil and the onion and fry for 4-5 minutes until softened, add the tomato purée and cook out for 1 minute, then add the Garlic Granules, tomatoes, Smoked Paprika, Crushed Chilies, sugar and season with Schwartz Sea Salt to taste. Simmer for 10-15 minutes until thickened.
When the potatoes are done transfer to a serving bowl, cover with the tomato sauce and serve.