- In a pan add butter and once it melted add the onions and garlic. Saute until onions are soft and translucent. Stir in the Italian seasoning, pepper flakes, salt, and pepper followed by veggies and cilantro. Give it a good mix and cook for 1-2 mins. Take it off the heat and let it cool slightly. In a mixing bowl, add softened cream cheese, tomato ketchup, shredded mozzarella, and vegetable filling. Mix until well combined and divide it into portions. Apply butter to both the bread slices facing up. Place one portion of the filling and spread it evenly. Top it with another bread slice. Apply some butter on top. Heat a grill pan on medium flame and place the sandwich with the butter side down. Cook for 2 mins. Apply some butter to the side facing up and flip to cook until golden brown. Serve hot.