01 - Combine yogurt, lemon juice, garam masala, cumin, coriander, chili powder, turmeric, and salt in a large bowl. Add chicken pieces and toss to coat thoroughly. Cover and refrigerate for at least 30 minutes, up to 4 hours for deeper flavor penetration.
02 - Mix grated carrots, squeezed zucchini, peas, and red onion in a large bowl. Add chickpea flour, all-purpose flour, baking powder, cumin, coriander, chili flakes, and salt. Stir in eggs until fully combined. Set aside while preparing chicken.
03 - Heat vegetable oil in a large skillet over medium-high heat. Add marinated chicken pieces and cook until browned and nearly cooked through, approximately 5–6 minutes. Remove chicken from pan and set aside.
04 - Add butter to the same pan. Sauté chopped onion for 3–4 minutes until softened. Add minced garlic and grated ginger, cooking for 1 minute until fragrant. Stir in crushed tomatoes and sugar. Simmer for 10 minutes, stirring occasionally.
05 - Return browned chicken to the pan. Pour in heavy cream and simmer gently for 10–12 minutes until chicken is fully cooked and sauce has thickened. Adjust seasoning with salt to taste.
06 - Heat ½ inch vegetable oil in a large frying pan over medium heat. Drop spoonfuls of batter into hot oil, flattening slightly with the back of the spoon. Fry for 2–3 minutes per side until golden brown and crisp. Transfer to paper towels to drain excess oil.
07 - Plate butter chicken and garnish generously with chopped fresh cilantro. Arrange warm vegetable fritters alongside. Serve immediately while fritters remain crisp.