Discard the most outer 2 leaves then wash and dry lettuce. Finely slice crosswise into 1cm (1/4 inch) ribbons. Divide shredded lettuce between two bowls.

For the sauce place cashews, soy sauce, lime juice, lime zest (if using) and 1/2 cup water in a tall jug or bowl. Using your stick blender puree until you have a creamy sauce. Or use your blender or food processor. Taste and season with salt and more lime (if needed).

Scatter cooked protein over the top of the lettuce bowls. Finish with big dollops of the cashew 'sour cream'. Serve hot sauce at the table for everyone to add their own.