• Adjust rack to top position and preheat oven to 425 degrees. Wash and dry produce. • Cut potatoes into 1/2-inch-thick wedges. Halve, core, and thinly slice green pepper. Halve, peel, and thinly slice half the onion (whole onion for 4 servings). Peel and mince garlic. • Toss potatoes on a baking sheet with a drizzle of olive oil, salt, and pepper. • Roast on top rack until golden brown and crispy, 20-25 minutes.

• While potatoes roast, in a small bowl, combine ketchup, mustard, stock concentrate, ponzu, cornstarch, 1⁄3 cup water (1/2 cup for 4 servings), and 1 tsp sugar (2 tsp for 4).

• Heat a drizzle of olive oil in a large pan over medium-high heat. Add green pepper and cook until slightly softened, 2-3 minutes. • Add sliced onion and cook until veggies are browned and tender, 4-6 minutes more. Season with salt and pepper. • Transfer to a medium bowl; cover to keep warm.

• Heat a drizzle of olive oil in pan used for veggies over medium-high heat. Add beef* and cook, breaking up meat into pieces, until browned and cooked through, 4-6 minutes. TIP: If there’s excess grease in your pan, carefully pour it out. • Stir in garlic and cook until fragrant, 30 seconds. • Add sauce and bring to a boil. Cook until thickened, 2-3 minutes. Stir in 1 TBSP butter (2 TBSP for 4 servings) until melted. Season with salt and pepper.

• Evenly top beef filling with mozzarella; cover pan until cheese melts, 1 minute. Remove pan from heat. • Halve and toast buns.

• Fill buns with beef filling and veggies. Divide sandos between plates; serve with potato wedges on the side.