平凡だ
The taste is ordinary.
味が平凡です
The taste at this restaurant is ordinary.
この食堂は味が平凡です
The taste at this restaurant is ordinary considering the price.
この食堂は値段は味が平凡です
The taste at this restaurant is ordinary even though the price is high.
この食堂は値段は高いのに味が平凡です
The taste at this restaurant is ordinary even though the price is high, because the seasoning is weak.
この食堂は値段は高いのに味付けが弱いので味が平凡です