Cedar Planked Shrimp with Parsley Pesto Sauce

food safe, cedar planked board, soaked for 2 hours

21-25 shrimp, cleaned and deveined and patted dry

large bunch of Italian parsley

the zest of 2 lemons

large garlic clove, finely grated on a microplane

or more of red pepper flakes

olive oil to loosen the pesto