Preheat the oven to 425f.
Place the flour, sugar, baking power, cream of tartar and salt into a large bowl and stir to combine.
Add in the diced butter and using a pastry blender, work the butter into the flour mixture i¡until you have pea size pieces.
Make a well in the centre of the mixture and add in the milk, cheese and thyme and stir gently until you have a formed dough.
Turn out onto a floured surface and pat the dough until you have a flat surface and it is around half an inch in thickness.
Use a biscuit cutter to cut out rounds and transfer to a lined baking sheet.
Brush the tops of each biscuit with a little milk and sprinkle over a little more cheddar cheese.
Place in the oven to bake for around 10-12 minutes until the bottoms turn golden.
Transfer to a wire rack to cool then get inventive with your fillings.