Add the escarole a few handfuls at a time, stirring after each addition so that they start to wilt, 1 to 2 minutes. Add 1/4 teaspoon kosher salt and toss to combine. Continue to cook, stirring occasionally, until the escarole is just tender, 2 to 4 minutes. Remove the pan from the heat. Add the lemon juice and stir to combine. Taste and season with more kosher salt as needed.