Peel and finely chop the shallots. Sauté in 1 teaspoon of hot fat. Fill up with chicken stock, add peas. Season with salt and pepper. Bring to the boil briefly and puree. Remove the crusts from the toast, cut into small cubes and fry in the remaining hot fat until golden brown.
Break langostinos out of their shells down to the tail end. Fry in hot oil for about 2 minutes. Season with salt and pepper. Serve soup garnished with mint.