Adjust racks to top and middle positions and preheat oven to 450 degrees. Wash and dry all produce. Dice potatoes into 1/2-inch pieces. Trim and halve zucchini lengthwise, then slice crosswise into 1/2-inch-thick half-moons.

Lightly oil a baking sheet. Tear bread into small pieces. In a medium bowl, mix bread and 3 TBSP water together until they form a chunky paste. Add beef, Tuscan Heat Spice, 3/4 tsp salt, and a pinch of pepper. Gently mix until combined. Shape mixture into two 1-inchtall loaves; press down to flatten slightly. Place on prepared sheet and bake on top rack until cooked through, 20-25 minutes.

Meanwhile, place potatoes in a medium pot with enough salted water to cover by 2 inches. Boil until tender, 15 minutes. Reserve 1/2 cup cooking water, then drain and return to pot. Mash over low heat with 2 TBSP butter and a splash of cooking water (start with 2 TBSP) until smooth. Stir in a drizzle of olive oil. Season with salt and pepper. Keep covered until ready to serve.

In a second medium bowl, combine zucchini, a drizzle of olive oil, 1/2 tsp oregano (save the rest for another use), salt, and pepper. Spread onto a second baking sheet. Roast on middle rack, flipping halfway through, until browned and tender, about 15 minutes.

In a small bowl, combine tomato paste, stock concentrate, 2 TBSP water, and 1/4 tsp sugar.

Once meatloaves are cooked through, evenly brush with glaze. Sprinkle with cheese. Turn oven to broil (or heat to 500 degrees) and broil until cheese has melted, about 2 minutes. Divide meatloaves, zucchini, and mashed potatoes between plates.