Preheat oven to 425°F. Combine potatoes, lemon zest, 1 tbsp olive oil, and a pinch of salt and pepper on one side of foil-lined baking sheet and toss. Roast until potatoes are starting to brown, 15 minutes. Remove sheet from oven. On other side of sheet, combine zucchini, 1 tbsp olive oil, nutritional yeast, and a pinch of salt and pepper and toss. Roast until potatoes and zucchini are golden brown, 10 to 12 minutes. (4-serving meal: use 2 tbsp olive oil, 2 tbsp olive oil)

Stir together cornstarch, broth concentrate, lemon juice, and 1 cup hot water in medium bowl and set aside. (4-serving meal: use 4 tsp cornstarch, 2 cups water)

Heat 1 tbsp olive oil in large nonstick skillet over medium heat. Add tofu and cook until browned and crisp, 2 to 5 minutes per side. Transfer to plate and cover to keep warm. Wipe skillet clean. (4-serving meal: use 2 tbsp olive oil)

Heat butter in same skillet over medium heat. Add shallot, garlic, and a pinch of salt and pepper. Cook until soft and fragrant, 2 to 3 minutes. Stir in broth and bring to a boil. Cook until slightly thickened, 2 to 3 minutes. Stir in capers. Add crispy tofu and simmer until warmed through, 1 to 2 minutes.