From Williams Sonoma - TK
In a small bowl, beat the eggs with the salt until they are homogenous. Heat a 2-quart (2-l) saucier over medium-low heat and add the butter. When the butter has melted, strain the beaten eggs through a sieve into the pan. Cook, continually whisking the eggs, until they thicken yet are still very creamy and not completely set. Whisk in the crème fraîche and cook for a few seconds longer. Spoon the eggs onto warm serving plates and serve immediately. Serves 2.
Substiture creme fraiche, with a mix of 2 T heavy cream and 1t unsweetened natural yogurt.