Clutch in. E Brake on (remove the catch in the handle so when you let go, it just drops), wait for your go point with the revs up high, slip the clutch enough to keep the revs up while letting go of the E Brake, profit.
This is going to be tough on your clutch because keeping the revs up means that as you launch, you need to not fully let go of the clutch or it drops way down and out of boost.
Anti lag isn't the answer either unless you're willing to buy several turbos a year.