Melt butter in medium saucepan over medium heat
Once melted- whisk in flour to make a roux - cook 1-2 minutes
Slowly add milk & water - whisking briskly to fully incorporate & keep milk from scalding
Keep whisking 5-8 minutes to thicken sauce
Remove from heat, add french onion mix, teriyaki, cheese & parsley - whisk in well
Ladle over your grilled chicken
garnish with additional parsley after plating.