Mix the eggs with the butter and milk in a large pot. In a separate bowl mix the flour, sugar, baking powder, salt, chocolate and walnuts. The dry mixture is poured in one portion to the liquid mixture and stirred gently several times with a spoon or spatula. Divide the mixture in the form of muffins, which was previously greased or paper cups are placed. Bake in preheated oven at 200 degrees Celsius for approximately 25-30 minutes or until ready.