My neighbor gave me seeds to plant and this is what is growing. What is it called? how do I cook/serve/prepare it? Is it ready to pick now or should it get bigger?
That is a winter squash. Leave them on the vine until the rind is very hard. You can use it in any winter squash or pumpkin recipe. Typically the squash is cut into chunks and steamed or baked before using in the recipe.
Here is a link that might be useful: Kabocha squash recipes