Heat the broiler.
Combine the kale pulp, mayonnaise, Parmesan, lemon zest and juice and 1 cup of the Gruyere in a bowl and mix to combine. Transfer the mixture to a 9-inch pie dish or medium ovenproof skillet and top with the remaining 1 cup Gruyere.
Place under the broiler until the cheese starts to brown and the mixture starts to bubble, about 5 minutes. Serve warm with chips or crostini.
If you don't have a juicer, substitute 1 1/2 cups finely chopped kale for the kale pulp.