In a small bowl, mix the yogurt, 1 teaspoon salt and lemon zest.
Line a large sieve or colander with cheesecloth or clean, thin (flour sack style) dish cloth; set over a large bowl. Place the yogurt mixture in the colander. Gather edges of cheesecloth to cover yogurt. Place in refrigerator and let drain for 4-6 hours (longer if you want it to be thicker).
Gently squeeze out any excess liquid over the sink, set aside.
Heat oven to 375 degrees F.
In a small bowl mix the honey, olive oil, cinnamon, ginger, salt and crushed red pepper flakes.
Lay the sweet potatoes out on a rimmed baking dish in a single layer. Drizzle the honey mixture over the potatoes. Roast, tossing occasionally, for 35-40 minutes in oven or until tender.Drizzle with more extra-virgin olive oil.
Spread the labneh onto a platter and top with the roasted sweet potatoes. Drizzle with extra olive oil and sprinkle with parsley, green onions and flakey sea salt to taste.