Crusted Hake with Radishes and Turnips

Name: Crusted Hake with Radishes and Turnips
Ingredients: 2 tablespoons extra-virgin olive oil, plus more for frying; 12 radishes with greens, halved, greens chopped; 4 very small turnips, cut into 3/4-inch-thick wedges; Kosher salt; Pepper; 1/2 cup all-purpose flour; 2 large eggs, beaten; 1 cup Cream of Wheat cereal; Four 5-ounce skinless hake fillets; 2 tablespoons unsalted butter, cubed; 6 ounces (10 cups) stemmed curly spinach (not baby); 1 1/2 tablespoons whole-grain mustard; 1 1/2 tablespoons fresh lemon juice