There is a dish I would like to make, but I need more of a certain vegetable to do so. I was planning to grow it from seeds in the greenhouse, but if you'd like to help...
Grow plants in the greenhouse. Take Dedue's seeds and ask the greenhouse keeper how to grow and harvest crops.
  1. Accept the quest from Dedue.
  2. Do some gardening in the greenhouse.
  3. Report to Dedue.
You have my gratitude. The greenhouse is an invaluable resource. If we cultivate more plants, I'm sure we'll be able to cook a larger variety of meals.