I‘d love to try and make this but as an overseas follower I have to ask: What in the world is cream of tartar? Please help.

You could contact www.Mccormick.com
They are a major spice company and they could tell you where it might be available near you. Or, order some directly from them...

Another name is potassium hydrogen tartrate. It's a white powder similar in texture to baking powder(not baking soda) you might have to look in the pharmacy stores. That is where I had to get baking soda when I was living in France. Www.allrecipes.com has a decent article on it.

Cream of tartar is the salt of tartaric acid, also known as potassium bitartrate. It is a byproduct of winemaking. It helps to stabilize meringues, makes them fluffy and slows down the weeping. If you can't find it in your local area, you can substitute with lemon juice or white vinegar.