Vegetarian Chickpea Tikka Masala

Name: Vegetarian Chickpea Tikka Masala
Ingredients: 2 (15-ounce) cans chickpeas (drained); 3 tablespoons butter; 1 onion (medium, chopped); 1 1/2 tablespoon ginger garlic paste; 1 (8-ounce) can tomato sauce; 1 cup half and half; 1/4 teaspoon cayenne; 1 lemon juiced (juiced); 1 tablespoon Garam Masala; 1 (14.5-ounce) can diced tomatoes (undrained); 1 bell pepper (sliced); 1 teaspoon paprika; 1 1/2 teaspoon salt; 2 tablespoons fenugreek leaves (optional); 4 tablespoons cilantro; cooked rice or cauliflower rice (to serve)