Blanch the green beans in lightly salted water for about 3 minutes, until soft. Then put the beans in ice water to stop the cooking process. Throw the beans in a colander, let the water drain.
Heat a large skillet over high heat, add the bacon and fry until crispy on all sides, for about 8-10 minutes. Put the fried bacon on a paper towel and remove almost all the fat from the pan (leave about 2 tablespoons of fat in the pan).
Put mushrooms and shallots in a pan with the fat and fry over medium heat, stirring occasionally, for about 5 minutes. Put the blanched beans in a frying pan and add red pepper, fry the green beans with mushrooms for 1-2 minutes. Break the cooled bacon into small pieces and pour into a frying pan with beans. Salt and pepper the beans with mushrooms and bacon