Having a bunch of spinach to use up I came across this recipe. It's been a favorite for the summer!
Heat a 10-inch skillet over medium, then melt butter, 30 seconds to 1 minute. Stir in about three-quarters of the scallions (saving some of the green parts for garnish) and garlic, and cook until softened, stirring frequently, about 3 minutes.
See notes… Stir in spinach, adding in batches if it doesn’t all fit in the pan at once, and ½ teaspoon salt. Continue to cook, stirring occasionally, until spinach is wilted, about 5 minutes.
Stir in stock and bring to a simmer. Stir in orzo, lemon zest and remaining ½ teaspoon salt. Cover and simmer over medium-low heat until orzo is nearly cooked through and most of the liquid is absorbed, 10 to 14 minutes, stirring once or twice.
Stir in cheese, peas (if you like) and dill, cover the pan, and cook for another 1 minute, to finish cooking and warm the peas. To serve, sprinkle with more cheese and the reserved scallions.
Note: Add the baby spinach leaves at the end of cooking—the heat of the finished dish will wilt it quite adequately.