Step 1: Preheat the oven to 350 degrees F.
Step 2: In a small bowl, stir together the oats and milk. Thinly slice 1/4 of the onion and set aside. Finely chop the remaining onion. In a large bowl combine the turkey, oat mixture, chopped onion, bell pepper, eggs, Worcestershire sauce, ketchup, herbs, salt and a few grinds of pepper. Mix just until well combined.
Step 3: Transfer the mixture to a 9 by 13-inch baking dish and shape into a loaf about 5 inches wide and 2 1/2 inches high or in a large-medium loaf pan.
Step 4: Pour the tomato sauce over the meatloaf and sprinkle with the sliced onions.
Step 5: Bake for about 1 hour or until an instant-read thermometer registers 160 degrees.F. Remove from the oven and let rest for 10 to15 minutes before slicing.