Ok, after reading the reviews of the quiches ending up soggy, I did alter a few of the portions the recipe called for. First off, the biggest problem maker is the amount of milk this recipe calls for! An entire cup of milk is simply too much. Use 3 tablespoons instead! I also used 4 whole eggs (instead of 5) and 3 egg whites.
When cooking the mushrooms, really make sure you cook them until all the water is absorbed (this too will help with the soggyness). Also, add a dash of salt while cooking them to help with absorbing the water.
I filled each muffin cup 3/4 full of the egg mixture and 2 tablespoons of the sausage mixture! The muffin cups were filled to the very top and then topped with a little more shredded swiss (parmesan will also work) They will spill a bit over when baking but nothing you can't trim with a butter knife (and eat)!
BAKING: 325 degrees is way too low and 25 minutes-not enough! I baked at 350 for 45 minutes. Quiches were fully cooked, nice and crispy golden crust all over and not to mention delicious! I think i'll try hot turkey breakfast sausage next time for a little more spice!
Hope this helps everyone!