Melt butter in a cast iron skillet over medium heat. Add the diced onion, carrot, peas, and corn and cook, stirring occasionally, for 5-7 minutes or until softened and beginning to brown. Add the garlic, herbs, salt, and pepper and cook for an additional 1-2 minutes.
2 tablespoons unsalted butter, ½ large yellow onion, 2 large carrots, 1 cup sweet corn, ½ cup green peas, 3 cloves garlic, 2 teaspoons fresh thyme leaves, 1 teaspoon fresh rosemary, ½ teaspoon kosher salt, ½ teaspoon black pepper
Add the flour, tomato paste, and soy sauce to the ground turkey mixture and stir well to combine. Pour in the chicken stock and simmer until slightly thickened. Remove the skillet from the heat. If using a casserole dish, transfer the filling to the casserole dish.
1 tablespoon all-purpose flour, 1 tablespoon tomato paste, 1 teaspoon low-sodium soy sauce, ½ cup chicken stock