Preheat oven to 400 degrees.

Zest lemon & squeeze the juice into a small bowl. Whisk in the zest, butter (or margarine), parsley, salt, pepper, & green onions.

Place tilapia fillets in a casserole dish or baking pan. I like to like mine with tinfoil sprayed with nonstick cooking spray. Top with the butter mixture. Bake fillets for 15 minutes, or until fish flakes easily with a fork.