How can plants make food without sunlight?
They can't. Plants need sunlight, water, and soil to grow or to produce anything. So it is unable to make food without sunlight.
Green plants use a process called photosynthesis to make food from sunlight. Only green plants can make their own food. Other plants (like mushrooms) and animals do not make their own food, but get nutrition from green plants (or dead green plants). Animals do not make food from sunlight. If they could, they would not need to eat.