This is an improvisation that seems to work well. Put tofu in food processor and process until smooth. Remove and drain on paper towels for 5 min. Drain the beans and put all ingredients for cheese mixture in processor.
Process untill smooth and combined.
Put milk in a saucepan. Add flour slowly while whisking. Heat over medium heat until boiling while stirring constantly. Continue to heat until thickened. Remove from heat and stir in spinach.