This Red Potato & Red Onion Gratin is a savory layered bake that combines tender new potatoes with the sweet, mellow bite of red onions, all tied together with thyme and a light buttery finish. It’s a rustic yet refined dish that brings out the natural flavors of its simple ingredients. Baked until golden and slightly crisp at the edges, this gratin is a comforting side dish perfect for family dinners, potlucks, or any meal needing a cozy touch.
Ingredients
- 2 lbs new potatoes (peeled and sliced ¼" thick)
- 3 tbsp oil (divided)
- 3 red onions (medium, sliced ¼" thick)
- ½ tsp thyme
- 1 tsp salt (divided)
- ½ tsp pepper (divided)
- 2 tbsp butter (finely diced)
- Parsley (for garnish (optional))
Instructions
Step 1: Prep Potatoes
- Place sliced potatoes in a bowl of cold water.
- Change water 2 or 3 times to remove excess starch.
Step 2: Cook Onions
- Heat 1 tbsp oil in a skillet over medium heat.
- Add onions and thyme.
- Cover and cook, stirring occasionally, for about 10 minutes until onions are wilted but still slightly crunchy.
- Drain potatoes and pat dry.
Step 3: Assemble Gratin
- Preheat oven to 425°F.
- Grease a shallow 2-quart casserole dish with 2 tbsp oil.
- Arrange half of the potato slices in overlapping circles on the bottom.
- Season with ⅓ of the salt and pepper.
- Sprinkle half of the cooked onions over potatoes.
- Repeat layers, finishing with potatoes.
Step 4: Bake
- Dot the top with butter.
- Bake uncovered for 30 minutes, until potatoes are tender and edges are golden.
- Garnish with chopped parsley, if desired.
Tips
- Substitute sweet onions for red for a milder flavor.
- Add ½ cup grated Gruyère or Parmesan cheese between layers for a cheesy twist.
- Use dried rosemary or oregano in place of thyme for a different herb profile.
- Make it a main dish by adding cooked bacon or sausage between layers.
Nutrition
Calories: 221kcalCarbohydrates: 36gProtein: 4gFat: 7gSaturated Fat: 1gPolyunsaturated Fat: 2gMonounsaturated Fat: 4gTrans Fat: 0.04gCholesterol: 1mgSodium: 299mgPotassium: 732mgFiber: 4gSugar: 6gVitamin A: 13IUVitamin C: 34mgCalcium: 43mgIron: 1mg
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