Meaning
とろろ蕎麦 (とろろそば, tororo-soba) is Tororo soba — a Japanese food.
What is Tororo soba?
Tororo-soba (とろろ蕎麦) is also known as yamakake-soba (やまかけ蕎麦). It consists of soba noodes topped with tororo , the puree of yamaimo ( Dioscorea japonica ), a potato-like vegetable.