Preheat oven to 425 degrees F. Blend pesto and butter together in a food processor. If you want to make your own, use our Homemade Pesto Recipe.
Spread the butter onto a sheet of plastic wrap. Wrap the plastic around the butter, rolling it back and forth to shape it into a cylinder. Twist the ends tightly. Chill until ready to use.
Brush fish fillets with melted butter and season with salt and pepper. Dust with Panko, pressing them into the fillets to adhere. Heat a large saute pan over medium-high; add oil and saute fish for 3 minutes. Carefully turn each fillet, add tomatoes to pan, and transfer to the oven to roast for 10 minutes. Serve each fillet with a tablespoon of Pesto Butter and Tomatoes.
Steam carrots and green beans and serve on the side.