Roast sweet potato at 400°F for 30-40 minutes until soft
Slice red onion thinly and caramelize in a sauté pan with 2 tbsp olive oil and ½ tsp salt on low heat for 30 minutes until soft and sweet, adding water if needed
Combine 2 tbsp chopped shallots, ½ tbsp minced garlic, 1 tbsp harissa paste, 3 tbsp raw tahini, ¼ cup lemon juice, ½ cup greek yogurt, 3 ice cubes, pinch of black pepper, and 1 tbsp olive oil in a food processor
Blend harissa-tahini sauce for 30-45 seconds until combined
Rub butter on each half of the roasted sweet potato
Season sweet potato with salt
Pour harissa-tahini sauce on top of sweet potato
Add caramelized onions on top
Garnish with chopped cilantro and serve
