There are several simple recipes here on the JC website for succulent salt beef and perfect pastrami:

Anne Shooter's herbed and spiced version is super simple and adds a tiny twist to tradition. Start with pickled brisket, so no need to brine your beef. 

For purists who want to start from scratch, is Stephen Lamb's brined version, which uses pure drived vacuum salt for the brining process, which you'll need to buy in advance. 

To turn the the pickled brisket (which has been brined) into pastrami, you add a smokey flavour, cover it in a spicy rub, and cook it dry in the oven. Ben Tish's recipe, may take a few days, but adds so many layers of sweet and smoky flavour, you won't regret it.