Preheat the oven to 325 degrees. In a medium skillet over medium-low heat, heat the olive oil until shimmering. Add the onions, thyme, 2 teaspoons salt, and 1 teaspoon pepper and cook until the onions are translucent but not browned, about 15 minutes.
Stir in the Worcestershire sauce, chicken broth, and tomato paste. Remove from heat and cool to room temperature.
In a large bowl, combine ground turkey, bread crumbs, eggs, and cooled onion mixture. Mix well and shape into a rectangular loaf on an ungreased baking sheet. Spread the ketchup evenly on top.
Bake until the internal temperature is 165 degrees and the meat loaf is cooked through, about 1 1/2 hours. Serve hot, room temperature, or cold in a sandwich. (A pan of hot water in the oven, under the meat loaf, will keep the top from cracking.)
Ground turkey: Look for 93% lean ground turkey (99% lean will be too dry for meatloaf).
Bread crumbs: It's easy to make your own bread crumbs and for the tastiest results, I highly recommend it. Or, substitute store-bought.
Ketchup: Using a sauce like ketchup keeps the meatloaf moist. But, you could use a different sauce such as your favorite BBQ sauce, or bake the meatloaf plain and make a gravy or marinara sauce for serving.
Yield: This recipe makes 1 very large loaf of Turkey Meatloaf. You can get at least 10 slices out of it, more or less depending on how you cut it.
Storage: Store leftovers covered in the refrigerator for up to 4 days.