Preheat oven to 425°F. Combine sweet potato, lemon zest, 1 tbsp olive oil, and a pinch of salt and pepper on foil-lined baking sheet and toss. Roast until sweet potato chips are tender and beginning to brown, 15 to 20 minutes, rotating halfway through.

Heat 2 tbsp olive oil in large nonstick skillet over medium-high heat. Add onion, garlic, and a pinch of salt and pepper and cook until onions are translucent, 5 to 7 minutes. Add cumin and broccolini and cook until tender, 8 to 10 minutes. Turn off heat, add lemon juice, and cover to keep warm.

Stir together mayo, harissa, and a pinch of salt in small bowl.

Place ciabatte, cut side up, directly on oven rack and toast until golden, 2 to 3 minutes. Spread harissa mayo on top and bottom halves of toasted ciabatte. Place bottom half on each plate, add 5 to 6 sweet potato chips, top with cumin-spiced broccolini, and close sandwiches. Serve with extra sweet potato chips. Enjoy!

For 4-serving meal, double all ingredients. You may need to cook in batches, in larger cooking vessels, or for longer cook times. Follow visual cues in 2-serving recipe.