Step 1

Whisk lemon zest, lemon juice, red pepper flakes, and ½ cup oil in a small bowl to combine; season vinaigrette with salt and pepper.

Step 2

Season fish all over with salt and pepper. Heat 2 Tbsp. oil in a large skillet over medium. Add asparagus, garlic, beans, and ¼ cup water; season with salt and pepper. Cook, stirring occasionally, until asparagus is crisp-tender and beans are warmed through, about 4 minutes. Transfer to a medium bowl; stir in 2 Tbsp. vinaigrette. Reserve skillet.

Step 3

Heat remaining 2 Tbsp. oil in reserved skillet over medium. Cook fish, stirring occasionally, until golden brown and flesh flakes easily with a fork, 5–7 minutes.

Step 4

Add fish and ½ cup herbs to bean mixture and stir once. Drizzle with more vinaigrette and season with more salt and pepper. Just before serving, scatter more herbs on top.