Begin by placing your 1 kg of beef cubes in a large mixing bowl. Add a generous amount of vindaloo paste, ensuring each piece is well-coated. Cover and refrigerate for at least 30 minutes, ideally overnight.

Heat 3 tablespoons of neutral oil in a skillet over medium-high heat. Add 2 cups of chopped onions and sauté until translucent, about 2-3 minutes. Stir in 3 chopped garlic cloves and cook for another minute until fragrant.

Sprinkle in ½ teaspoon of ground turmeric and 1 teaspoon of red chili powder, stirring well to toast the spices for about 30 seconds. Add 2 chopped medium tomatoes and 2 tablespoons of tomato paste, cooking until the tomatoes break down, about 2-3 minutes.

Incorporate your marinated beef and 1 teaspoon of white sugar into the spice mixture. Stir together and cook for about 10 minutes until the beef begins to brown.

Pour in 1 cup of water. Bring to a boil, reduce heat to low, cover, and simmer for approximately 1 hour.

Check the sauce consistency. If too thin, switch to sauté mode and simmer uncovered until thickened, stirring occasionally.