If you’re craving the wonderful bounty of fresh, summer produce right about now, take heart. Plenty of fruits and vegetables are harvested during late fall into winter and can be easily prepared for a big boost of nutrition and fresh, new flavor.

Why we need extra nutrition now: Time spent indoors in the winter increases exposure to cold and flu viruses. That makes it even more important to shore up your immune system with vitamin- and antioxidant-rich fruits, veggies and nuts such as those suggested below. These foods also tend to be lower in calories, a good contrast to rich, cold-weather comfort foods.

Four particularly healthy and tasty winter foods available from the end of November into March that you may not have tried before…

Winter food #1: Delicata squash.Like other winter squash, delicata, named for its delicate green- and gold-striped skin, is high in a variety of nutrients, including fiber—one cup cubed has nearly 6 g of fiber. Fiber helps prevent constipation, regulates blood pressure and makes you feel full, useful for weight control. Naturally sweet delicata also contains beta-carotene, an antioxidant linked to reduced cancer and heart disease risk. And it offers potassium for additional help with blood pressure management.

With delicata, there’s no peeling necessary—the skin becomes soft and edible when cooked.

Easy recipe: Slice a delicata squash in half, scoop out the seeds, then slice into one-inch strips. Spread the strips on an oiled baking sheet, season with salt and pepper to taste and roast at 375°F for 15 minutes per side or until golden brown. Enjoy plain, or with a sauce—one teaspoon of Dijon mustard, one tablespoon of maple syrup and a squeeze of lemon juice. Serves: Two.

Winter food #2: Blood oranges. These juicy beauties owe their vivid, purple-hued interior to anti-inflammatory compounds called anthocyanins. Compared with regular oranges, blood oranges contain more of this compound, an antioxidant linked to reduced cholesterol and heart disease risk. They’re slightly more tart than regular oranges but just as high in vitamin C, crucial for immune function, and vitamin A, which promotes healthy vision.

How to use: Simply peel and eat them as you would any citrus fruit…juice them…or peel and quarter and add to salads or oatmeal (they taste great with cinnamon and pumpkin seeds). Smart combo: Full-fat or low-fat plain yogurt and blood oranges. The yogurt’s fat facilitates absorption of the orange’s vitamin A.

Winter food #3: Chestnuts. These tree nuts, with their earthy, sweet potato–like flavor, are rich in energizing complex carbs…manganese, which is needed for optimal brain function…vitamin B-6, which helps boost the immune system…and copper, which helps fuel metabolism. And they’re a lot lower in fat than most nuts.

Shopping tip: Look for chestnuts with tight, shiny skins…and ones that are heavy for their size—this indicates that they are fresh. If you hear noise in the shell when you shake one, it’s probably not fresh.

No need to roast chestnuts on an open fire, you can simply use your oven. You’ll want about one pound of chestnuts for four people…

How to prepare: Preheat the oven to 425°F. Firmly grasp each chestnut between your thumb and index finger, making a long slice in the shell across the rounded top with a serrated knife. Place the chestnuts in a pot of water over medium heat and bring to a boil. Then drain and transfer the chestnuts to a baking sheet. Roast for 15 to 20 minutes, transfer to a bowl, cover with a towel and let steam for 15 minutes. Peel off the outer shell and tough brown skin and serve. Add salt or seasonings to taste and enjoy. Roasted, chopped chestnuts also make a nice addition to veggie or rice side dishes.

Winter food #4: Jicama. This crunchy, mildly sweet veggie is a staple of crudité platters, but it can be enjoyed cooked as well. Sometimes called the Mexican potato, jicama contains a type of fiber called inulin, a prebiotic that acts as fuel for probiotics, the healthy bacteria living in the gut. Plus, it offers vitamin C, potassium and iron.

New way to use: Shred and mix with chopped apples, pears, walnuts and dried fruit for a tasty salad.

Another option: Peel (a vegetable peeler works well) and slice one medium jicama into french fry–shaped slices. Toss with one tablespoon of olive oil, one-half teaspoon each of cumin, chili powder, garlic powder and turmeric and one-quarter teaspoon each of salt and pepper. Spread on a baking sheet lined with parchment paper and roast at 450°F for 50 to 60 minutes, tossing once after 30 minutes. Serves: Four.