Cook spinach in a very small amount of boiling water for 5 minutes, and drain. Melt butter in a saucepan. Add flour, and whisk until smooth. Still whisking, gradually add milk. Cook until thickened and bubbly. Add cheese, stirring until it melts. Remove from heat.

Beat egg yolks on medium with an electric mixer until thick and pale. Add cooked spinach, salt, garlic and lemon juice until all are blended together. Gradually stir in hot cheese mixture, stirring mixture constantly.

Beat egg whites on high until stiff. Gradually fold egg whites into spinach mixture. Pour into eight buttered individual soufflé dishes or 6 oz. custard cups. Bake at 400 degrees for 10 minutes. Reduce heat to 350 degrees and bake 35 to 40 additional minutes or until puffed and golden. Serve immediately.