Soak the broad beans in a generous amount of slightly salted water and leave to soak the day before. The bean will triple in size during soaking, so choose the right container. Don't forget a little salt to prevent it from going sour. Cook them when they are soaked, they should be soft, but not overcooked. Strain and leave to cool.
Cover unshaved, medium-sized carrots with water, add a little salt and cook until they start to soften. Drain the water and leave to cool. Then, peel and cut into cubes.
Cut a medium-sized onion. Pour the mushrooms into a sieve to drain. Prepare oil, pepper, marjoram, mayonnaise. When all the ingredients are ready and "at hand", heat a large pan. Everything has to fit and still have room for mixing.
Heat a little oil (I cook everything with extra virgin olive oil) and fry the onions until they caramelize easily. Peel the carrots. If the oil is lacking, add a little, but do not overdo it, as it will all remain in the mixture. Fry the carrots until they start to turn yellow. Season with pepper, add marjoram. By the way, marjoram works wonders here. I tried adding Herbes de Provence, it's delicious, but not quite it.
Next are the beans, they don't need to be fried for a long time. I turn off the stove as soon as I mix. Everything! Cooking is complete.
Add the mushrooms to the cooled mass and mix in a spoonful of mayonnaise. Mayonnaise is an auxiliary ingredient here, it's delicious without it, but a small amount ties everything together. Do not increase it in any way, it is not necessary, after all, the mixture already contains oil, fried onions, and herbs.