1. Preheat oven to 400°.Combine first 4 ingredients in a small bowl; set aside.
2. Microwave potatoes in a large glass bowl covered with plastic wrap on HIGH 4 minutes. Drain potatoes, if necessary, and stir in garlic, salt, pepper, and 1 teaspoon olive oil. Set aside.
3. Cook bacon in a large cast iron or ovenproof skillet over medium-high heat until crisp; remove bacon, and drain on paper towels, reserving 1 teaspoon drippings in skillet. Add remaining 1 teaspoon olive oil to skillet over medium-high heat; add cod fillet, and cook 1 minute on each side.
4. Spoon reserved potatoes around cod; bake 3 minutes.
5. Remove from oven, and spread reserved butter mixture over fish. Return to oven; bake 5 more minutes or just until fish flakes with a fork and is opaque in the center. Sprinkle with cooked bacon; garnish, if desired. Serve immediately.