For the Yellowtail:

4 - 6 oz. yellowtail fillets
2 Tbsp. olive oil
1 tsp.black pepper
1 lb. new potatoes or fingerlings
1 lb. chanterelle mushrooms
4 Tbsp. olive oil
Salt and pepper to taste

For the pesto:

½ cup fresh parsley
2 Tbsp. fresh mint
1 Tbsp. fresh cilantro
1 Tbsp. fresh oregano
2 garlic cloves
1 cup olive oil
Juice of 1 lemon, or to taste
Salt to taste
Optional: pinch of red pepper flakes

Put all ingredients for the herb pesto into blender or food processor and process until finely mixed, then adjust seasoning with salt and lemon juice. 

Rub the fillets with 2 tablespoons olive oil and season with salt and pepper and set aside. Toss potatoes and mushrooms separately with 2 tablespoons olive oil each and salt and pepper to taste. Place the potatoes in a hot cast iron pan and roast at 425° for 15 minutes, then add the chanterelles to the pan and continue roasting until fish is done. In another hot cast iron pan, place the fish fillets skin side down. Roast the fish 6 minutes on the skin side then carefully flip and finish cooking until just cooked through. Plate the potatoes and mushrooms, top with yellowtail, and drizzle with the herb pesto.