Peel, wash, and grate the 2 carrots. Peel and wash the 2 onions, then chop finely.
Heat a frying pan over medium heat and add 2 tablespoons vegetable oil. Add the chopped onions and grated carrots, stirring occasionally, for about 5 minutes until the onions are golden.
Cut the 0.5 kg beef liver into pieces and grind into a fine paste using a food processor or meat grinder.
In a bowl, combine the ground liver, 2 eggs, 3 tablespoons flour, 30 ml milk, 0.5 teaspoon baking soda, 1 teaspoon salt, and 0.3 teaspoon ground black pepper. Mix until smooth.
Heat a frying pan over medium heat and lightly brush with vegetable oil. Pour slightly less than a ladle of batter into the pan and spread evenly across the entire pan.
Fry the liver pancake for 1 minute on the first side, then flip and fry for 1 minute on the second side until fully cooked.
Repeat steps 6–7 with the remaining batter until all pancakes are cooked.
Layer one cooked liver pancake on a serving plate, then spread the caramelized onion and carrot mixture on top and drizzle with mayonnaise.
Continue stacking the remaining pancakes, spreading the onion-carrot mixture and mayonnaise on top of each layer.
Spread the 20 g soft butter across the top layer.
Sprinkle the chopped fresh greens over the top.
Using mayonnaise, draw a spider web pattern on top for decoration.
Cover and refrigerate for 24 hours before serving.