This colorful Mediterranean-inspired gratin combines earthy roasted beets, naturally sweet sweet potatoes, creamy feta cheese, crunchy walnuts, and fragrant herbs. Beautiful enough for a holiday table and delicious enough for a cozy weeknight dinner!
Prep time
20 minutes
Bake time
45–60 minutes
Servings
6
Ingredients
For the vegetable layers
- 2 medium sweet potatoes, peeled and thinly sliced
- 2 medium beets, peeled and thinly sliced
- 2 medium Yukon Gold or other waxy potatoes, thinly sliced
- 2 tablespoons extra-virgin olive oil
- 3 cloves garlic, minced
- 1 teaspoon dried thyme
- ½ teaspoon dried oregano
- ½ teaspoon salt, or to taste
- ¼ teaspoon freshly ground black pepper
For the topping
- 1 cup (150 g) crumbled feta cheese
- ¾ cup (75 g) chopped walnuts
- 2 tablespoons fresh parsley or dill, chopped
- 1 tablespoon extra-virgin olive oil
- 1 teaspoon lemon zest, optional
Optional creamy mixture
- ½ cup (120 ml) vegetable broth
- ¼ cup (60 ml) heavy cream or unsweetened cooking cream
Instructions
1. Prepare the vegetables
Preheat the oven to 375°F (190°C). Lightly grease a baking dish. Peel the beets and sweet potatoes, then slice all the vegetables into thin, even rounds, approximately ⅛ inch (3 mm) thick.
2. Season the slices
In a large bowl, combine olive oil, garlic, thyme, oregano, salt, and pepper. Toss the vegetable slices until lightly coated.
3. Layer the vegetables
Arrange the slices upright in overlapping rows, alternating sweet potato, potato, and beet slices to create a colorful pattern. Pour the optional broth and cream around the vegetables, not over the entire surface.
4. Bake until tender
Cover loosely with foil and bake for 35–45 minutes. Carefully remove the foil and check the vegetables with a knife. They should be beginning to soften.
5. Add feta and walnuts
Sprinkle the crumbled feta and chopped walnuts over the vegetables. Return the dish to the oven uncovered for another 10–15 minutes, until the vegetables are tender and the top is lightly golden.
6. Garnish and serve
Let the gratin rest for 5–10 minutes. Finish with fresh herbs, a drizzle of olive oil, and optional lemon zest. Serve warm.
Nutrition Information
Estimated per serving, assuming 6 servings and including feta and walnuts but excluding the optional cream and broth.
| Nutrient | Approximate amount |
|---|---|
| Calories | 300–360 |
| Protein | 8–11 g |
| Carbohydrates | 30–38 g |
| Fat | 17–23 g |
| Fiber | 5–7 g |
| Sugar | 7–10 g |
Values vary with vegetable sizes and the quantities of feta, walnuts, and olive oil used.
Nut Information
- Tree nuts: Contains walnuts.
- Peanuts: Not required.
- Dairy: Contains feta; optional cream adds more dairy.
- Gluten: The basic recipe is naturally gluten-free, provided all packaged ingredients are suitable.
- Allergy alternative: Omit walnuts if needed and add pumpkin seeds for crunch, provided seeds are safe for the person eating the dish.
Questions & Answers
1. Can I prepare this gratin ahead of time?
Yes. Slice and season the vegetables, arrange them in the baking dish, cover, and refrigerate for up to 24 hours. Add the feta and walnuts near the end of baking.
2. Do I need to cook the beets before layering?
No, provided the slices are thin and the dish is baked until tender. For thicker slices or quicker cooking, partially cook the beets first.
3. Can I make it without cream?
Absolutely. Use vegetable broth or simply olive oil. The finished gratin will be less creamy but still flavorful.
4. Can I replace walnuts with another topping?
Yes. Try pumpkin seeds, sunflower seeds, or chopped pecans if suitable for your dietary needs.
5. Which feta cheese works best?
Traditional brined feta gives a tangy, salty flavor that complements the sweet vegetables. Crumble it evenly over the top.
6. How do I prevent the gratin from becoming watery?
Use a modest amount of broth, avoid overcrowding wet vegetables, and bake uncovered during the final stage to allow excess moisture to evaporate.
7. Can I add other vegetables?
Yes. Thinly sliced zucchini, parsnips, or carrots can be added, although their cooking times may differ.
8. How should I store leftovers?
Refrigerate in an airtight container within two hours of cooking and enjoy within 3–4 days.
9. Can I freeze this gratin?
You can, but the vegetables may become softer after thawing. Cool completely, portion into freezer-safe containers, and freeze for up to 2 months for best quality.
10. What should I serve with this dish?
It pairs well with grilled chicken, baked fish, lentils, chickpeas, or a crisp Mediterranean cucumber and tomato salad.
Helpful tip: Slice the vegetables evenly so they cook at the same rate. If the beets are much firmer than the potatoes, give them a short head start in boiling water before assembling the gratin.
