1. In a bowl, add all the ingredients and knead well to mix.
2. Lay a spring roll wrap flat, tip down. Place the filling mixture centered on the wrap. Roll up tightly. Dab a little 'glue' mixture along the edges to seal, then roll as per picture. Repeat until you use up all the filling mixture.
3. Pour oil (1~2cm) in a wok or a large saucepan and heat on medium-high until hot : Stick in a bamboo chopstick, if bubbles appear, it's hot enough. Place the rolls gently in the oil and cook from all sides, turning occasionally, until nicely and evenly golden. Transfer to a plate lined with paper towels to drain the excess oil. Repeat with the remaining spring rolls.
1. Place potatoes in large saucepan and add enough water to cover. Bring to a boil. Reduce the heat to medium-low, cover and simmer for 15 to 20 minutes or until easily pierced with a fork. Drain well.
2. Transfer potatoes in a bowl and add the ingredient A (butter, sugar and salt), then mash the potatoes until creamy with a potato masher or fork. Place the mashed potatoes into your ovenware. Set aside.
3. Make the beef topping : In a skillet, heat 1 tbsp olive oil and fry the garlic until fragrant. Add onion, beef and mushrooms, continue stir frying until it becomes wilted. Add the ingredient B to season and simmer for a few minutes.
4. Add sour cream and mix, stir for a few more minutes.
5. Preheat the oven to 200C° degree.
6. Sprinkle cheese over the mashed potatoes and pour the beef mixture over the cheese.
7. Bake in the preheated oven for 30 to 35 minutes.