Boil the tomatoes with water in a saucepan until the skin peels.

Remove from heat and let cool slightly.

Peel the skin off the tomatoes and remove the core. Roughly chop the tomatoes, keeping the juices.

Heat olive oil in a large saucepan over medium heat.

Add chopped garlic and onions and stir until softened.

Add the chopped tomatoes, basil leaves, salt, sugar, and black peppercorns.

Stir to combine.

Use a hand blender to coarsely puree the ingredients to get a saucy texture.

Cover the pan with the lid slightly ajar and simmer the mixture for 20-30 minutes until the sauce is thick.