Drain the beans, reserving about 60 ml of liquid. In a food processor, combine beans, garlic, salt, and bean liquid (or oil). Blend until silky smooth, adding a bit more liquid or oil as needed to reach a thick sour‑cream or mashed‑potato consistency. Taste and adjust salt and garlic.

For the onion topping: heat oil in a wide skillet over medium-low. Stir in sliced onions and ½ tsp salt; cook gently until golden and caramelized (about 8–10 minutes).

Stir in tomato paste, sugar (if using), and paprika. Cook for another 2 minutes until aromatic, sticky, and well combined. Remove from heat.

Transfer bean puree to a shallow serving plate and spread evenly. Pile the caramelized onions in the center. Drizzle a little extra oil over the top if desired.

Serve at room temperature or warmed. Traditionally accompanied by crusty bread, pickles, and sometimes smoked sausage.