Preheat oven to 425 degrees F. To a microwave-safe medium bowl, add potatoes and 1/2 cup water. Season with salt and pepper. Cover with vented plastic and microwave until mostly tender, 6 to 8 minutes. Remove plastic, drain water and let potatoes cool slightly.
To a large rimmed parchment-lined baking sheet, add green beans and 1 tablespoon oil. Season with salt and pepper. Toss to combine. Move beans to cover one-third of baking sheet.
Evenly distribute potatoes next to green beans on baking sheet. Using a potato masher or fork, gently smash each potato to 1/2" in height. Drizzle 1 tablespoon oil over potatoes and season with salt and pepper.
Add fish fillets to baking sheet. In a small bowl, combine remaining 1 tablespoon oil, mustard and lemon juice. Brush mustard mixture on top of fish. Bake 20 to 25 minutes, until potatoes are crispy and fish flakes easily with a fork. Garnish with herbs to serve, if desired.
Source: Hannaford fresh Magazine, October November 2024