Prep Time: 25 to 30 minutes
Preheat oven to 350 degrees. Cut zucchini into ⅛ each circles (using as much of the zucchini as you wish) and set aside. In a medium bowl, whisk six eggs with salt, pepper, garlic (thinly chopped or pressed) and milk, put to the side. Coat the bottom of an 8 to 10 inch cast iron (or oven-proof) skillet, with olive oil; arrange half the zucchini slices so that they cover the bottom.Place in the oven for 4 to 5 minutes or until the zucchini begins to brown around the edges; then remove.
Carefully pour the egg mixture into the skillet, using the rest of your zucchini to create a second layer. Bake for 15 to 20 minutes. Check in on the eggs regularly using a knife to poke the frittata; the frittata is fully cooked when the inserted knife is free from egg and the frittata is golden brown.Turn the oven to broil. Add the blue cheese and Nduja to the frittata and place back in the oven for 2 to 3 minutes. Watch to avoid burning. Remove from oven, and set on table to cool before serving.