Cut ciabatta bread into 4 equal sections and then cut each section in half lengthwise. Spread tomato pesto onto the bottom of each ciabatta section. Top with roasted tomatoes, fresh tomatoes, basil leaves, and mozzarella.
Brush grill with olive oil. Place panini onto press and heat until cheese has melted, about 8–10 minutes (depending on the brand and type of press you use).