In a small bowl, combine ketchup, sugar, and mustard. Set aside.
In a large bowl, combine seasoning, ground beef, egg, and water. Using your hands or a large spoon, mix until well blended. Press mixture into Rectangular Steamer or 8” x 4” silicone loaf pan.
Place steamer on microwave-safe plate. Cover; cook on high 4 min. Spread prepared sauce over meatloaf; cover and cook on high an additional 2–3 min or until internal temperature reaches 160° F. Or, spread prepared sauce over meatloaf; place steamer on a Sheet Pan lined with Sheet Pan Liner. Bake, uncovered, in preheated 350° F oven for 35–40 min.
Per serving: Calories 260, Fat 13 g (Saturated 5 g, Trans 0.4 g), Cholesterol 120 mg, Sodium 490 mg, Carbohydrate 11 g (Fiber 1 g, Sugars 6 g), Protein 25 g.
If you have extra time, let the meatloaf rest in the steamer 10 min before unmolding and slicing.