Prepare the vegan mayonnaise. In a container for an immersion blender, pour 3 tablespoons of liquid from under the beans, lemon juice, put sugar, mustard and salt.
Whisk, gradually adding a thin stream of vegetable oil, until thick. Do not make a double portion at a time - it may be badly whipped.
Cut the tomatoes into cubes, add to the salad, season with mayonnaise, and mix.
Tomatoes can be taken and ordinary, but in winter I prefer cherry.