Spinach

Spawns as part of a Leafy Garden (Frost Garden - As of version 1.8.9) Spinach leaves can be crafted (shapeless) into seeds and planted in tilled dirt

Spinach plants can be right-clicked to harvest and it leaves the plant to grow again.

Recipes
Stock  =  Pot + Spinach

Steamed Spinach  =  Pot + Spinach + Water

Spinach Pie  =  Bakeware + Dough + Spinach + Cheese + Toast

Beef Wellington  =  Raw Beef or Firm Tofu + Dough + Any Mushroom + Spinach