"Kottu" comes from the Tamil word that means "to chop".
The roti, along with other ingredients like egg and meat, are fried on a hot cast-iron flat griddle while being chopped and mixed repeatedly by the chef using heavy spatulas.
"In Sri Lanka, you will hear the 'clang clang clang' sound of street vendors making kottu roti even before you smell the delicious aroma or see the meal," Mayadunnage said.
Each vendor has their own beat and rhythm when using their blades. Mayadunnage admits to sometimes dancing while he cooks the dish.
Kottu at Walawwa comes in many forms - from classics like chicken kottu, egg kottu, fish kottu and lamb kottu to a chicken and cheese variant.
Madushani, or Shani as she is fondly known to friends and customers, runs front of house at the restaurant.
Opening the restaurant with her husband was challenging but one of the best decisions they've made since migrating here.
"Sri Lankan food is not so common like Chinese, Indian or Thai and I was so homesick for the flavours of home when we first moved here," Shani said.
"Having this restaurant has helped us settle better, and our aim is that it will also help cure some of the homesickness for other Sri Lankans who crave a taste of home."
Walawwa's menu offers other Sri Lankan street favourites including hoppers, string hoppers, polsambol, pittu and lamprais.
But Shani says her favourite is the pol roti - unleavened flatbread made with shredded coconut, flour, coconut milk and spices.
Growing up, Shani used to make pol roti for family dinners with her mother and grandmother.
"Pol roti is so much a part of my Sri Lankan childhood, and I often helped my mum and grandma roll them and flip them. It really was a special bonding time for us," she said.
"Especially this year when we can't get to travel or see family, eating pol roti is one way of transporting me back to my loved ones in my mind."
Pol roti can be accompanied with any side dish or eaten plain. It is so versatible that Sri Lankans eat it for breakfast, lunch, dinner and even as a snack.
Shani's favourite is pol roti with crab curry, especially her hubby's crab curry - which is also on the menu at the restaurant.
"Crab curry is kind of a luxury, and can be a bit messy to eat. But it is fun, especially when it is shared with good friends and family," she added.
Sri Lankan cuisine is famous for particular combinations of herbs and spices with fish, meats and vegetables. There's heavy use of cinnamon, black pepper and jaggery made from kithul palm syrup.
The couple want Walawwa to be a home away from home for the Sri Lankan diaspora here. Judging from the response from my mate Channa, they seem to have done so.