Step 1

In a large, deep skillet with a lid, heat the oil over medium heat until shimmering. Add the onion and cook until softened, about 3 minutes. Add the orzo and cook, stirring, for 2 minutes more. Add the broth, water and 1/4 teaspoon salt and bring to a boil. Reduce the heat to medium-low, cover and simmer, stirring once or twice, until the orzo is about halfway cooked, about 5 minutes.

Step 2

Stir in the spinach, peas, dill, lemon juice, the remaining 1/4 teaspoon salt and the pepper and cook until the spinach is just wilted, 1 to 2 minutes. Nestle the fish into the orzo, then cover and cook, stirring once or twice, until the fish is cooked on the outside but still quite rare inside, 3 to 4 minutes. Add 1 to 2 tablespoons of water to the pan if it seems dry.

Step 3

Sprinkle the feta over the top, cover and continue to cook until the cheese softens and the fish is cooked to your liking, 2 to 4 minutes more. Serve right away.