Rhowch y blawd i mewn i bowlen fawr, yna ychwanegwch y burum a'r siwgr. Gwnewch ffynnon yn y canol, rhowch 200ml o ddŵr cynnes a phinsiad mawr o halen i mewn, a chymysgwch gan ddefnyddio llwy bren nes bod y blawd i gyd wedi'i ymgorffori a bod gennych does meddal. Trowch allan ar arwyneb â blawd ysgafn a thylino am 5 munud nes ei fod yn llyfn. Rhowch y toes mewn bowlen, gorchuddio â lliain sychu llestri glân a'i neilltuo i orffwys am 5 munud. (Gallwch adael y toes i godi ymhellach os oes gennych amser, ond nid oes ei angen ar gyfer crwst tenau.)

Tip the flour into a large bowl, then stir in the yeast and sugar. Make a well in the middle, tip in 200ml warm water and a large pinch of salt, and mix using a wooden spoon until all the flour has been incorporated and you have a soft dough. Turn out onto a lightly floured surface and knead for 5 mins until smooth. Tip into a bowl, cover with a clean tea towel and set aside to rest for 5 mins. (You can leave the dough to rise further if you have time, but it’s not required for a thin crust.)