Lemon - Grate both lemon skin and white pith, its filled with phyto-nutrients. Use juice, skin and pith in teas and to flavor winter dishes.
Parsley - Garnish winter dishes with FRESH parsley. Add it to soups, casseroles, pasta, etc.
Apple - In the winter make warm fresh apple sauce: Remove apple core steam apple or apples. Mash with a little maple syrup or agave.
Red Lentil - Easy to prepare. Great source of protein and fiber for$1 per serving. My favorite recipe is NY Times Easy Red Lentil Soup.
Miso - Excellent warming, winter-healing food. Good source of protein and food for the gut probiotics!!! Less than $1 per serving
Coconut and Coconut Milk are the latest boutique "miracle cure," This one, however, seems to have some real science behind it. It has been found to give us a lot of health benefits including help with blood pressure, diabetes, and a lot more. And it is yummy, although many brands are tasteles so pick the good ones. Also use the unsweetened kind and add your own Stevia or Agave Nectar. I sometimes mix it with Almond milk. Really good.
This is a good video on the benefits of Coconut Milk.