Preheat the broiler and roast the roma tomatoes on a baking sheet until the skins are charred and blistered.
Toast the sesame seeds in a small dry skillet over medium heat for 2-3 minutes until they are golden and fragrant.
Place the roasted tomatoes, toasted sesame seeds, olive oil, and lemon juice in a blender and pulse until a smooth, thick achar sauce forms.
In a large mixing bowl, combine the ground chicken, minced red onion, cilantro, ginger, garlic, cumin, coriander, turmeric, sea salt, black pepper, and melted ghee.
Lay out the wonton wrappers and place a generous tablespoon of the chicken filling in the center of each.
Moisten the edges of the wrappers with water, fold them over the filling, and pleat the edges tightly to create a sealed pouch.
Line a steamer basket with parchment paper and steam the momos over boiling water for 12 minutes until the chicken is cooked through and the wrappers are tender.