Melt 2 tbs butter in a cast iron skillet.
Add to a food processor, then add everything else except blueberries and 2 tbs butter.
Blend until smooth.
Melt remaining 2 tbs butter in the skillet, add blueberries and cook for 30 seconds.
Pour egg mixture over the blueberries, and bake on 450 until puffy and golden brown, about 15 minutes.
