First, we need to craft a mass fabricator. It takes 2 cables, an HV transformer, 2 advanced circuits, an advanced machine, 2 glowstone dust and a recycler.
Then, we need to build a power system to power the machine. HV is optional, but highly recommended. Remember that the Mass Fabricator is the only machine which directly accepts HV current (and also remember that HV + other machines = KABOOM)! This power system uses a single generator, but you can create an even bigger one depending on your resources.
Feeding the generator some coal...
And after the matter generator is fed a total of 2 million EU from the HV, it generates UU-Matter.
Here's my improved grid, used from now on on this tutorial:
It's recommended that you feed the Mass Fabricator with some secret material in the middle (lightning bolt). Doing so will speed it up a bit.
The progress bar will slowly start filling...
...and this is after a minute or so... ...then one more minute... ...almost there...
...and we have UU-Matter!
All matter recipes are secret, find them yourself (a hint: all matter recipes exclusively use matter, nothing else, but this may change in the future). Matter can create many valuable and invaluable items, like this DIAMOND!