1. Season prawns with pepper and salt.
2. Heat oil in a wok, drop in prawns and deep-fry until golden brown. Remove and set aside.
3. Melt butter in a wok, add in chopped garlic and brown sugar, stir-fry until fragrant. Add in salted egg yolks and stir-fry until fragrant. Add in grated Mozzarella cheese and mix well.
4. Add in fried prawns and toss evenly, dish up and serve.