INTRODUCTION
Simple Oven Roasted Onions are an easy side dish that works with many meals. You only need a few common ingredients and one pan. The oven brings out a sweet, rich taste in the onions. You will find they are soft on the inside and slightly brown on the outside. They add warm flavor to meat, fish, and grain bowls.
If you like simple roasted veg, you might also enjoy a crunchy green side like the roasted peanut kale crunch salad. This onion recipe is quick, kind to your schedule, and great for busy nights.
WHY YOU WILL LOVE THIS RECIPE
You will love this recipe because it is simple and reliable. It uses humble ingredients that you probably have at home. The olive oil and lemon lift the taste, and the rosemary adds a warm herb note without being loud. The mustard helps the oil and lemon stick to the onion, making each wedge juicy and flavored. After roasting, the onions become sweet and mellow. They also look nice on the plate with brown edges and soft centers.
This recipe is flexible. You can change herbs or swap one type of onion for another. It is also easy to scale up for more people. You can make it for a family dinner, a weeknight meal, or a small party. The work is small: trim, cut, toss, and roast.
HOW TO MAKE Simple Oven Roasted Onions
This section walks you through the general flow of the recipe and what to expect as you cook. Start by trimming and peeling the onions, then cut them into wedges so they roast evenly. Mix the olive oil, lemon, mustard, garlic, rosemary, salt, and pepper in a bowl to make a light dressing. Toss the wedges in the dressing so each piece has some oil and flavor. Spread them on a baking pan so the heat can reach all sides. Roast in a hot oven until they are tender and have brown edges. Turn them once so they cook evenly.
If you want a fuller roasted plate, try pairing these onions with the roasted chickpea and sweet potato bowl for a complete and warm meal. This small mix of sides makes a meal feel special without a lot of work.
EQUIPMENT NEEDED
- A rimmed baking pan or sheet pan.
- A medium bowl for the dressing.
- A sharp knife and a cutting board.
- A whisk or fork to mix the dressing.
- Oven mitts or a towel to handle the hot pan.
These tools are basic and most home kitchens have them. Use a rimmed pan so juices do not spill. A metal pan will give a bit more browning, but a glass pan also works.
Ingredients You’ll Need :
- 2 medium red onions
- 1 medium sweet yellow onion
- 1/4 cup extra virgin olive oil
- 1 lemon, juiced
- 1 teaspoon Dijon mustard
- 3 cloves garlic, minced
- 2 sprigs fresh rosemary, stems removed and chopped
- 1 teaspoon kosher salt
- 1/2 teaspoon freshly ground black pepper
These amounts serve about 3 to 4 people as a side. You can double or triple the amounts for a larger group. If you like a stronger lemon flavor, add a little more lemon juice. If you do not have Dijon mustard, a small smear of yellow mustard will work, though the taste will be different.
STEP-BY-STEP INSTRUCTIONS :
Preheat oven to 400 degrees F. Trim both the root and stem sides of the onion, leaving the root intact. Peel onions and cut into wedges. Place onions on a baking pan. In a medium bowl, combine olive oil, lemon juice, mustard, garlic, rosemary, salt and pepper, whisking until well combined. Pour the dressing over the onions and toss well. Bake for 30 to 45 minutes, until tender and browned, tossing once during cooking. Remove from the oven, toss again, and transfer to a serving bowl. Serve and enjoy!
HOW TO SERVE Simple Oven Roasted Onions
Serve these onions hot or warm. They go well with roasted meats like chicken, beef, or pork. They also pair nicely with fish and grilled vegetables. For a simple meal, place them on top of cooked rice or quinoa and add a handful of fresh herbs. You can add a little extra lemon juice or a drizzle of olive oil just before serving.
For a casual plate, toss them with cooked pasta and a bit of grated cheese. For a more formal plate, place a small bed of greens on each plate and lay the warm onions over the greens. The heat wilts the leaves slightly and makes a soft, tasty bed.
STORAGE & FREEZING : Simple Oven Roasted Onions
Store leftover roasted onions in an airtight container in the fridge for up to 4 days. Let them cool to room temperature before you cover and chill. When you reheat, warm them in a skillet or in the oven to keep some of the brown edges crisp. Avoid microwaving if you want a firmer texture, though the microwave will work for quick warming.
To freeze, place cooled roasted onions in a freezer-safe bag or container. Press out as much air as you can and freeze for up to 2 months. Thaw in the fridge overnight before reheating. Reheat in a skillet or oven to bring back more texture.
SERVING SUGGESTIONS
- Pair with roasted meat and a simple salad for a full meal.
- Top grain bowls with a few wedges for warmth and flavor.
- Serve on a tray with other roasted vegetables at a family meal.
- Add them to sandwiches or wraps for sweet, soft layers.
If you want a full set of roasted sides, try adding a bean or tuber dish like the roasted sweet potato black bean salad to make a varied and filling plate.
VARIATIONS
- Herb swap: Use thyme or sage instead of rosemary for a new herb note.
- Vinegar twist: Replace half the lemon juice with a splash of balsamic vinegar for sweetness and depth.
- Spice add: Add a pinch of red pepper flakes for a mild heat.
- Sweet option: Toss a spoon of honey or maple syrup into the dressing for a sweet glaze.
- Whole roasted onions: Roast whole onions at the same temp, but cook longer until soft through. These make a great presentation.
These small changes let you match the onions to different meals and tastes. Try one change at a time to see how it shifts the flavor.
FAQs
Q: Can I use other types of onions?
A: Yes. Yellow, white, or sweet onions will work. Red onions add color and a slightly sharper taste.
Q: How do I know when the onions are done?
A: The wedges should be soft when you pierce them with a fork and show brown edges. Cooking time depends on wedge size and oven, usually 30 to 45 minutes.
Q: Do I need to toss the onions during cooking?
A: It is best to toss once during cooking so they brown evenly. Tossing also helps the dressing coat all sides.
Q: Can I roast these at a different temperature?
A: You can roast at 375°F for a bit longer. A higher temp will brown them faster. Watch closely so they do not burn.
Q: Is it okay to skip the mustard?
A: Yes, you can skip it, but mustard helps the dressing cling to the onion and gives a mild tang.
Q: Can I roast these with other vegetables on the same pan?
A: Yes, but choose vegetables that have similar cook times. Cut larger roots smaller so they cook at the same pace.
MAKE-AHEAD TIPS FOR Simple Oven Roasted Onions
You can prepare the dressing and cut the onions a day ahead. Store the cut wedges in water in the fridge to keep them fresh. Dry them well before adding the dressing. You can also toss the onions in the dressing and keep them in a covered container in the fridge for a few hours before roasting. This makes the roast faster and lets the onions soak up more flavor.
If you need to reheat for a party, roast the onions until nearly done, cool, and store in the fridge. Finish roasting just before serving to bring back a fresh brown edge and warm center.
Simple Oven Roasted Onions
Ingredients
Method
- Preheat oven to 400 degrees F.
- Trim both the root and stem sides of the onions, leaving the root intact.
- Peel onions and cut them into wedges.
- In a medium bowl, combine olive oil, lemon juice, mustard, garlic, rosemary, salt, and pepper, whisking until well combined.
- Pour the dressing over the onions and toss well.
- Place the onions on a baking pan.
- Bake for 30 to 45 minutes, until tender and browned, tossing once during cooking.
- Remove from the oven, toss again, and transfer to a serving bowl.
- Serve hot or warm, alongside roasted meats or on top of grains.