In a large bowl, put in the flour, salt and sugar. Add in milk, cream and egg yolks. Beat with an electric mixer until ingredients are blended, occasionally scraping the bowl with a rubber spatula. Lastly add in the melted butter to mix.
Whisk egg whites and cream of tartar in a separate clean bowl until just stiff. Fold egg whites into the creamed mixture.
Heat up the waffle-maker until hot then spoon batter into the hot plates. Spread out evenly to cover the surface. Cover and cook according to the manufacturer?s instructions. (Do not lift cover during cooking.) When done, lift cover and loosen waffle with a fork then transfer to a wire rack.
Repeat until all the batter is used up. Serve the waffles with honey, jam, kaya or even ice-cream.