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Roasted Potatoes and Onions turns everyday ingredients into a deeply flavorful side dish that’s always welcome. It’s all about celebrating the natural flavors of its components, a blend of silky Yukon Gold potatoes and sweet, tender onions. It’s a near effortless recipe that transforms basic ingredients into a robust and comforting companion to any main course.

Roasted Potatoes and Onions photographed from the top.

In this recipe, thin slices of potatoes and onion wedges are gently tossed in olive oil, then spread out on a baking sheet for even roasting. As they roast, the edges of the potatoes turn irresistibly crispy, while the onions soften and caramelize, releasing their natural sweetness. A sprinkle of fresh thyme or rosemary adds a fragrant touch. Whether it’s a quiet weekday meal or a holiday feast, this dish is sure to impress with its simplicity and depth of flavor.

Ingredients for Roasted Potatoes and Onions

Roasted Potatoes and Onions Ingredients on a granite surface.
  • Potatoes: Choose Yukon gold or another waxy variety. Look for firm potatoes with smooth, unblemished skins. Avoid any with sprouts or green spots.
  • Red Onion: Select a large, firm red onion with a bright, shiny outer skin. It should feel heavy for its size and have no soft spots or visible signs of decay.
  • Olive Oil: Choose a cold-pressed extra-virgin olive oil for its robust flavor. Look for a fresh, fruity aroma and a color that ranges from green to golden yellow.
  • Fresh Thyme or Minced Fresh Rosemary: Fresh herbs should look vibrant and green without any yellow or brown parts. If using rosemary, choose sprigs with a strong, piney aroma.
  • Kosher Salt and Freshly Ground Black Pepper
  • Flaky Sea Salt (Optional): If using, select a salt with a light, flaky texture (such as Maldon). It should crumble easily between your fingers, which is ideal for finishing dishes.

3 Recipe Tips

  1. Slice Evenly: Do your best to slice potatoes to a uniform thickness for even cooking. A mandoline slicer can be very helpful for this.
  2. Avoid Overcrowding: Spread the potatoes and onions in a single, uncrowded layer on the baking sheet. This helps them to roast properly rather than steam.
  3. Testing for Doneness: The potatoes are done when they are tender inside and crispy on the edges. Similarly, the onions should have softened and be golden and richly browned (caramelized). Keep an eye on both towards the end of cooking time to prevent over-browning.
Roasted Potatoes and Onions photographed at an angle

Recipe Options

  • Substitute Yukon Gold potatoes with either sweet potatoes for their natural sweetness and soft texture, or Russet potatoes for a fluffier interior and earthy taste.
  • Replace red onions with sweet onions for a milder sweetness or white onions for a sharper, but still mild, flavor.
  • Squeeze fresh lemon juice over the dish just before serving to add a burst of citrus freshness.
  • Add a pinch of red pepper flakes with the herbs for a subtle spicy kick.
  • Mix in finely minced fresh garlic during the last 10 minutes of roasting to infuse the dish with a rich garlic flavor without the risk of burning.
  • Use dried herbs instead of fresh, halving the amount because of their concentrated flavor.
Roasted Potatoes and Onions close up with serving utensils.

How to Store

Store leftovers in an airtight container in the refrigerator for up to 3 days or freeze in a single layer and then transfer to a freezer-safe bag or container for longer storage (up to 3 months). To reheat, whether from the refrigerator or frozen, place them on a parchment-lined baking sheet in a 350°F (175°C) oven. Warm refrigerated leftovers for about 10 minutes and frozen ones for about 15 minutes, adjusting as needed, until they are heated through and crisp at the edges.

More Two-In-One Side Dish Recipes

How to Make Roasted Potatoes and Onions

Arrange potato slices in a slightly overlapping layer on a parchment lined baking sheet and evenly scatter red onion wedges on top, breaking them into smaller pieces for better caramelization. Drizzle all with olive oil and season with salt and pepper.

Bake in an oven preheated to 400˚F for 50-60 minutes, stirring every 10-15 minutes, until the potatoes are tender but crispy at the edges, and the onions have softened and caramelized. Once done, transfer to a serving platter, garnish with thyme leaves, and optionally, sprinkle with flaky salt and serve.

Roasted Potatoes and Onions

5 from 1 vote
Prep: 15 minutes
Cook: 1 hour
Total: 1 hour 25 minutes
Course: Side Dish
Cuisine: American
Calories: 263
Servings: 4 people
Tender potatoes with crisp edges and sweet, caramelized onions combine for a satisfying contrast in a versatile side dish for any meal.

Ingredients  

  • 1 1/2 pounds Yukon gold potatoes (or other waxy potato) thinly sliced
  • 1 large red onion halved and cut into 1/4-inch-thick wedges
  • 1/4 cup olive oil
  • kosher salt and freshly ground black pepper to taste
  • 1 tablespoon fresh thyme leaves or minced fresh rosemary
  • flaky sea salt such as Maldon, optional

Instructions 

  • Preheat oven to 400°F.
  • Line a baking sheet with parchment paper. Arrange potato slices in a thin, slightly overlapping layer and scatter red onion over the top in an even layer, breaking up some of the wedges into slivers that will caramelize. Drizzle olive oil, season with salt and pepper.
  • Bake 50-60 minutes, stirring every 10-15 minutes, until potatoes are tender with some crispy edges and onions are soft with some pieces that are caramelized. Transfer to serving platter; sprinkle with thyme leaves and finish with flaky salt if desired. Serve hot.

Nutrition

Calories: 263kcal | Carbohydrates: 33g | Protein: 4g | Fat: 14g | Saturated Fat: 2g | Polyunsaturated Fat: 2g | Monounsaturated Fat: 10g | Sodium: 12mg | Potassium: 767mg | Fiber: 4g | Sugar: 2g | Vitamin A: 87IU | Vitamin C: 38mg | Calcium: 34mg | Iron: 2mg

Nutrition information is automatically calculated, so should only be used as an approximation.

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4 Comments

  1. David @ Spiced says:

    5 stars
    Wow, those potatoes look fantastic! They’re so thin and golden. I could eat this entire pan! And these are the perfect side dish for almost any sort of dinner recipe.

    1. Marissa Stevens says:

      haha…they are addictive! Thank you, David.

  2. Mimi Rippee says:

    this whole baking dish of potatoes and onions could be my lunch today. Maybe with some sour cream.

    1. Marissa Stevens says:

      I love how you think, Mimi!