Cookbook: Portabello Burger

This past weekend boy and I was forcing despite his lack of interest showing boy the recipes I had pinned, trying to decide what to make for dinner and this portabello burger striked his fancy. He told me later that for some reason he though it was a burger just with mushrooms on it, but live and learn I suppose. I made the burgers (which took 2 hours of prep) and was sincerely let down. The mushroom didn't convey the balsamic flavor, the garlic on the bun wasn't potent enough, the mushroom took longer than stated to cook, the whole thing fell apart when bitten and the cheese kept sliding off the dome of the mushroom. Maybe I did it wrong, maybe it wasn't meant to be but overall, I probably won't make this again. I will however, modify it to be what was expected; a burger with mushrooms on it. Then I might have more luck.