You can add your meals to your grocery list by clicking the grocery basket icon on a meal tile. Edit your grocery list by clicking on the grocery icon in the top navigation bar.
To remove items you already have at home, click on the box next to an item. These items will move to a section at the bottom of the list called "Already Have These."
You can also change the quantity of an item by clicking on the item and increasing or decreasing the quantity.
To remove items completely, click on the item and select "Remove."
You can even add custom items by entering it in the text box.