Place potatoes in pan of boiling water and par-boil for about 8 minutes and drain.
Fry bacon until crisp and crumble.
In a 2.5 L casserole dish, layer 1/2 of each ingredient in this order: potatoes, salt, pepper, dot with butter, onions, green onions, basil, bacon, and cheese.
Repeat layers with rest of the ingredients.
Pour heavy cream over top and cover.
Bake for 30 minutes, remove cover and bake for another 15 minutes until top is slightly browned and bubbling.