Preheat oven to 450 degrees.
Toss potatoes with olive oil, rosemary, 1 tsp kosher salt and pepper.
Roast potatoes on a jellyroll pan at 450° for 20 minutes until golden and crispy.
While potatoes are roasting, melt butter in small saucepan or pot.
Add flour to melted butter, stirring to make roux. A little at a time, stir in milk. Heat on medium until sauce thickens.
Remove from heat; add parmesan and Durkees or mustard.
Whisk eggs in bowl and add small amount of heated milk mixture to temper.
Slowly combine tempered eggs and remaining milk mixture and whisk until smooth.
Season well with 1 tsp kosher salt and black pepper.
Spray loaf pan with cooking spray and place roasted potatoes in the bottom of the pan.
Top with mozzarella and ricotta cheese.
Pour eggs over potatoes but do not overfill.
Bake at 375° for 25-35 minutes until puffed and lightly browned. Eggs will fall once removed from oven.
NOTE: The cafe also serves a version with bacon or with just cheese (no potatoes in either), so feel free to experiment with extra ingredients. I think that this would be great with mushrooms too.
