Do you stir at all during the stove-top cooking portion?
I'm guessing not, since you have topped with cheese. I have been making frittatas for a long time from a Cooks Illustrated recipe, where you stir until the eggs start to get a little 'curdy' and your spatula leaves a bit of a wake in the pan.
Recipe question for: Cheesy Spinach & Artichoke Frittata With Arugula
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