Fit the largest fuel scoop you can and go exploring! I took a journey from HR 6421 to the California Nebula, about 1000ly, and scooped about 200 tonnes on the journey, so I'd anticipate a 1250ly journey to achieve this from scratch.
To boost this, just simply jump between two systems with scoopable stars at your max range (you consume more fuel for longer jumps than several smaller jumps) but I would find this very tedious, better to go explore a fairly close phenomenon