01 - Combine yogurt, lemon juice, cumin, coriander, turmeric, chili powder, garam masala, and salt in a large bowl. Add chicken pieces and toss to coat evenly. Cover and refrigerate for at least 20 minutes or up to 2 hours for optimal flavor penetration.
02 - Heat vegetable oil in a large skillet over medium-high heat. Add marinated chicken pieces and cook until golden brown and cooked through, approximately 6-8 minutes. Transfer browned chicken to a plate and reserve.
03 - Melt butter in the same skillet over medium heat. Add chopped onion and sauté until translucent and softened, about 5 minutes. Stir in minced garlic and ginger, cooking for an additional minute until fragrant.
04 - Add crushed tomatoes, tomato paste, sugar, and fenugreek to the skillet. Simmer uncovered for 10 minutes, stirring occasionally to prevent sticking, until sauce begins to thicken.
05 - Reduce heat to low. Stir in heavy cream and season with salt and pepper. Return seared chicken to the sauce and simmer for 5 minutes until heated through and evenly coated.
06 - Preheat oven to 350°F. Drape rotis or tortillas over inverted oven-safe bowls or ramekins to form bowl shapes. Bake for 7-8 minutes until crisp and lightly golden. Brush with melted butter immediately after baking.
07 - Carefully remove roti bowls from molds and place on serving plates. Fill each bowl generously with butter chicken. Top with a dollop of yogurt, sprinkle with fresh cilantro, add sliced red onion, and serve with lemon wedges.