Wash and peel 500 grams of potatoes, then cut them into 2-3 cm cubes. Soak the potato cubes in cold water for 10 minutes to remove excess starch. Drain and pat dry with a clean kitchen towel.

Heat 250 ml of oil in a deep frying pan over medium heat. Once the oil is hot, carefully add the potato cubes and fry them until they are golden brown and crispy. This should take about 10-12 minutes. Use a slotted spoon to remove the potatoes from the oil and place them on a plate lined with paper towels to absorb excess oil.

In a separate pan, heat 2 tablespoons of oil over medium heat. Add 1 finely chopped onion and 2 minced garlic cloves, and sauté until the onion is translucent and the garlic is fragrant, about 3-4 minutes.

Add 1 teaspoon of paprika, 1/2 teaspoon of cayenne pepper, and 1/4 teaspoon of cumin to the onion and garlic mixture. Stir well and cook for 1 minute.

Add 200 grams of crushed tomatoes, 1 tablespoon of tomato paste, and 1 teaspoon of sugar to the pan. Stir well and let the sauce simmer for 10-12 minutes, until it thickens.

Season the sauce with salt and pepper to taste. Pour the sauce over the fried potatoes and gently toss to coat them evenly.

Garnish the Patatas Bravas with chopped fresh parsley and serve immediately.