Chop the tomatoes, carrots, garlic, and potato. Place them in a pressure cooker with 1 1/2 cups water (about 350 ml) and table salt. Cook for 4 whistles. Let cool, then transfer to a blender jar. Add half a beet and blend until smooth. Strain to remove all pulp. Return the tomato pulp to the stove and cook again.

Add black salt and black pepper. Cook, stirring, for 15 to 20 minutes.

For the croutons, heat oil in a pan. Cut the 4 bread slices into small cubes. Fry the bread cubes in hot oil, stirring constantly, until golden brown. Serve the hot tomato soup topped with the croutons.