Preheat your oven to 425°F (220°C).
Spread the potato cubes on a baking sheet and drizzle with olive oil. Toss to coat evenly.
Season with salt.
Roast the potatoes in the preheated oven for about 25-30 minutes, or until they are golden brown and crispy, turning them halfway through.
While the potatoes are roasting, heat the olive oil in a skillet over medium heat.
Add the finely chopped onion and cook until it becomes soft and translucent.
Stir in the minced garlic, smoked paprika, cayenne pepper, and ground cumin. Cook for another minute until fragrant.
Add the crushed tomatoes, tomato paste, and sugar. Stir to combine.
Season with salt and pepper to taste.
Let the sauce simmer for about 10-15 minutes, or until it thickens slightly.
Stir in the red wine vinegar and adjust seasoning if needed.
Transfer the roasted potatoes to a serving dish.
Spoon the bravas sauce over the potatoes.
Optionally, garnish with chopped fresh parsley.
Enjoy your meal!