Preheat oven to 400 degrees F.

While oven is preheating, thinly slice onion. Half cherry tomatoes and kalamata olives. Heat about 2 tablespoons of avocado oil in an oven-safe skillet over medium-high heat.

Sauté onion until soft, about 5 minutes. Add sliced garlic cloves, tomatoes and olives. Cook for an additional 7 to 10 minutes, until tomatoes start to break down a bit and release their liquid.

Juice one lemon into the pan and nestle cod pieces into the center. Drizzle with a bit more olive oil and season well with kosher salt and cracked black pepper.

Place pan in preheated oven and bake for 14 to 16 minutes, until cod is cooked through.

Remove from the oven, top with fresh, chopped parsley (optional) and serve with roasted carrots or the sides of your choice.