Prep. time: 15 minutes
Cooking time: 20-30 minutes

You could mix some grated Gruyere or diced ham into the batter; diced salmon with garlic-herb fresh cheese, or flavor the batter with nutmeg. 

1. Preheat the oven to 180° C (350° F).
2. Melt the butter in a saucepan over low heat or on low power in the microwave. Let cool.
3. Beat 3 whole eggs; add the cold milk, salt and butter. Mix well.
4. Sprinkle in the quick tapioca, whisking constantly.
5. Let rest 10 minutes until thickened.
6. On a buttered baking sheet, form the batter into small mounds, placing in the center of each one a cube of Roquefort and some crushed walnuts.
7. Beat the remaining egg and brush the puffs with it.
8. Bake for 20-30 minutes until golden. Serve hot.