A while back I tried out a recipe for a savory crumb crust to use with quiche. It worked out well enough that I was planning to try it again using different crackers, but I took a look at the four Tablespoons of butter it adds to an already pretty fatty dish (and an increasingly fatty me) and decided against it.
Instead, I just laid a layer of breadcrumbs on the bottom of the pie pan to see how it would turn out. It required a bit of delicacy in placing the fillings (bacon, caramelized onions and spinach) and in pouring the egg mixture (three eggs, a quarter cup heavy cream, three quarters cup milk, three quarters cup semi-soft cheese, a quarter cup hard cheese, salt, pepper and a sprinkling of nutmeg), but you shouldn't be throwing that stuff around, anyway. I used Bittman's crustless quiche recipe from his Minimalist column in the New York Times. It called for mixing the cheese into the egg mixture instead of into the fillings which was an interesting difference from other recipes I've used.
Here's the result (after 20 minutes at 325 degrees).
And here's the bottom. Not much to see there, but it does give a bit of firmness to a rather loose and creamy quiche. Since the center was firm I thought I had left it in the oven too long, but really it could have used another five minutes. There was no browning, though, which was a bit of a disappointment. So it's not quite a success but I think there's promise.
For the last crumb crust I had laid down a layer of cheese just on top which I think melted through, insulating it from the main filling and holding it together. I'll try that with the bread crumbs next time.