Root Vegetable Gratin with Sweet Potatoes, Parsnips, and Beets
A cozy, layered gratin with naturally sweet root vegetables baked in a creamy herb sauce and topped with a golden, cheesy crust. Earthy, colorful, and perfect for a comforting side or vegetarian main.
🛒 Ingredients
🥕 Vegetables
- 2 medium sweet potatoes, thinly sliced
- 2 parsnips, peeled and thinly sliced
- 2–3 beets, peeled and thinly sliced (use gloves—they stain!)
- 1 small onion, thinly sliced (optional)
🥣 Cream sauce
- 1½ cups heavy cream
- 1 cup whole milk
- 3 garlic cloves, minced
- 1 tsp fresh thyme (or ½ tsp dried)
- 1 tsp rosemary, chopped (or ½ tsp dried)
- Salt & black pepper, to taste
- Pinch of nutmeg (optional, adds warmth)
🧀 Topping
- 1 cup shredded Gruyère or cheddar cheese
- ¼ cup grated Parmesan cheese
- 1 tbsp olive oil or butter (for brushing dish)
👨🍳 Instructions
1. Prep oven
- Preheat to 190°C (375°F)
- Grease a baking dish with butter or oil
2. Make cream sauce
- In a saucepan, warm cream, milk, garlic, thyme, rosemary, salt, pepper, and nutmeg
- Heat until just steaming (do not boil)
- Set aside
3. Layer vegetables
- Arrange sweet potatoes, parsnips, and beets in alternating layers
- Add onion slices if using
- Season lightly between layers
4. Add sauce
- Pour cream mixture evenly over vegetables
- Gently press down so liquid spreads through layers
5. Add cheese
- Sprinkle Gruyère/cheddar and Parmesan on top
6. Bake
- Cover with foil and bake 40 minutes
- Remove foil and bake another 20–25 minutes until golden and bubbling
7. Rest & serve
- Let rest 10–15 minutes before slicing (helps it set)
🍽️ Serving Ideas
- Serve with roasted chicken or lamb 🍗
- Pair with a crisp green salad 🥗
- Works as a vegetarian main with crusty bread 🥖
🔥 Tips
- Slice vegetables thinly for even cooking
- Use a mandoline for best texture
- Don’t skip resting time—it helps layers hold
- Add a drizzle of balsamic glaze for extra depth
🌈 Why it’s special
Sweet potatoes, earthy beets, and nutty parsnips create a natural balance of sweet and savory, while the creamy herb sauce and melted cheese turn it into a luxurious baked comfort dish.