I started by chopping up a cup and a half of muesli in an attachment to the immersion blender. Moving that to a bowl, I mixed in 2 tablespoons of olive oil and about 3 tablespoons of agave nectar until I had a good crumble going. Then, I patted down a layer of the crumble into the bottom of the pie dish.
I didn't think I'd have enough crumb for the top, so I mixed in about 2/3 cup of unbleached white flour and a bit more oil and agave nectar to moisten the mixture.
I chopped up a green apple, a peach, some strawberries, a handful of Ranier cherries, and some black raspberries, and tossed in some blueberries for good measure. I loaded up the pie plate with the fruit and pressed the crumb mixture onto the top of the pie.
I baked it until it was light golden brown (I probably could have baked it about 10 more minutes) at 325 degrees F, for fear of burning the agave nectar.
It's crunchy and nutty from the seeds and nuts in the muesli, and just sweet enough from the agave nectar (I erred on the less-is-more side because the cereal had dates and raisins in it), and just tart and wet enough from the fruit.
Next time, more fruit, less crumble, and a longer baking time to make the blueberries burst.