Try out the link below, this is the mash method I used for my Oberon like brew.
https://www.homebrewtalk.com/wiki/index.php/Decoction_mash#Enhanced_Double_Decoction
It does take a few more hours to brew but it helps to have a few extra brew pots, (I have 2 - 5 gal ss gal pots and use two...