OK, there are basically 2 routes here.
a) Big Money-Witch. Buy nothing except money and 2 Witches, until you can afford Provinces.
Variants here are:
- Open Feast to get to the Witch, but I think that is a bit weaker than just open Silver/Silver
- Open Militia/Silver to prevent your opponent from getting Witches. I don't know the starting decks here, but assuming 7 Coppers and 3 Estates, that might work. Problem here is that the Militia might collide later with your Witches, and with all the Curses flying aroung it's attack is not that strong, and often does nothing.
b) engine. As there is no trashing and no sifting against a Witch, that will get pretty hard. Probably not worth it, at least requires a lot of skill in engine-building.
You need lots of pieces to draw your deck, so Workshop seems key here. Anyway, you also must get to Witches because you don't want to eat all 10 Curses, you would prefer to win the split. That means build up engine fast, and try to play the Witch(es). Probably open Workshop/Feast, hope they don't collide, use Workshop to get Villages/Smithies, Feast for the Witch. Get a second WS, maybe a second Witch if enough Curses are left.
You probably will fall behind anyway, so go for the Duchies before getting the Provinces, a BigMoney deck filled with some Curses will have problems to get more than 5 Provinces, so you "just" need a better deck that can handle some Duchies (maybe WS->Feast->Duchy). Probably you want to build up as long as you can get away with it, TR, Lab, Market are all cards that will help you, but there are so many non-engine cards flying around without trashing and with Cursing, the longer I write about it the less I'm confident that an engine will do anything here if it's not played by some really experienced player. Dont' buy any Silver if you can get away with it, use Markets and one or two Golds for your income and rely on Workshop to get you your pieces for the engine.
Edit: Also Throne Room-Feast is a thing if you build an engine and can draw them together...