Do you keg or bottle? If you bottle its harder to achieve what you want without using extract.
Last summer I made SWMBO Slayer (Belgian Blonde) and then once beer cleared I transfered to keg, chilled and sort of "dryhopped" the keg with 3 lbs of frozen strawberries in bag and kept it cool. This way strawberries do not re-ferment, they just release sweet juices to beer and it comes out of tap exactly what you looking for. Very aromatic, sweet strawberry taste and zero tartness. It was incredible.
I don't think you can do it with bottles, unless you pasteurize or filter 100% of yeast prior to adding strawberries.