Preheat a panini machine. Spread soy hummus over one half of ciabatta. Top with sundried tomatoes, mesclun, soy yogurt and cheese. Cover with second half of ciabatta.
Spray panini machine with cooking spray. Place sandwich into machine. Close machine, and cook until bread is lightly toasted and mozzarella is melted, about 5 minutes. Alternatively, place sandwiches in heated skillet and weight with a heavy pan lid, cook until golden brown on both sides, turning once after about 4 minutes.