Fire and Dew Sweet Potatoes

Name: Fire and Dew Sweet Potatoes
Prep time: 10 min
Total time: 1 h 10 min
Cuisine: Canadian
Ingredients: 2 good-size sweet potatoes; 1 tablespoon (15 g) butter, plus more for brushing and topping; 2 tablespoons (30 ml) 2% milk; 1 egg, beaten; Salt, to taste; Black pepper, to taste