In a small bowl, combine 2 tablespoons of olive oil along with remaining ingredients (lemon juice and zest through black pepper); pour mixture over Mahi Mahi fillets then seal bag and turn to coat well.
Refrigerate for at least 30 minutes or up to 6 hours.
At time of cooking, heat remaining 1 tablespoon of olive oil in a large skillet over medium-high heat.
Add Mahi Mahi steaks and cook for 4 minutes per side or until fish flakes easily when tested with a fork.
In a large bowl, mix together the first 11 ingredients (ground chicken through the egg). With a small scoop, scoop out the mixture onto a parchment lined sheet pan.
Bake the meatballs in the oven for 15 minutes. Then pour over the tomato sauce and sprinkle over the Parmesan cheese. Return the meatballs to the oven and bake for 5-7 minutes more, or until the meatballs are cooked through and the sauce is bubbling.
Remove from the oven and let rest at least 5 minutes before serving.