Roasted Red Onions Recipe

Roasted Red Onions are a great flavor booster for salads, tacos, sandwiches, and grains. This 3-ingredient vegan recipe also makes a tasty side dish.

Course Condiment, Vegetarian Side Dish

Cuisine American

Diet Vegan

Prep Time 5

Cook Time 20

Total Time 25

Servings cup

Calories 293kcal

Preheat the oven to 400 degrees F. Line a baking sheet with parchment paper (or foil) and set it aside.
Peel the onions by removing the outer layer and inner papery skin. When cutting, you can either slice them in rings (and keep them whole) or split them into half-moon slices (and separate them.) Either way, for even baking, we recommend cutting them into ¼ inch slices.
Season them depending on how you cut them:
- Cut into rings: Place the red onion rings onto the prepared sheet pan on a single layer. Brush them on both sides with extra virgin olive oil and sprinkle them with salt and pepper (if using.)
- Sliced thinly: Gently break apart the slices and place them in a medium-sized bowl. Drizzle with olive oil and sprinkle with salt and pepper. Toss to combine. Spread on the prepared baking sheet on a single layer.
Roast, flipping (if you are cooking them as rings) or stirring (if you are baking them as thin slices) until softened and caramelized, for about 20 minutes*.
Remove from the oven, and let them cool slightly before using in your recipe.

Yields: This recipe makes 1 to ½ cups of roasted sliced red onions.
Baking time: During the recipe testing, we found out that the roasting time stayed the same for both cutting methods.
Storing: Let them cool to room temperature, place them in an airtight container and store them in the refrigerator for 3-4 days.
Reheating: You can enjoy this recipe either hot or cold, but if you prefer to serve them hot you can reheat them using one of the three methods below:
- Oven: Put the leftovers in an oven-proof baking dish with a splash of water. Roast them in preheated 350 degrees F. oven until heated through for about 8-10 minutes.
- Saute: Add the red caramelized onions to a saucepan with a little bit of oil (or water) and saute until thoroughly warmed.
- Microwave: Place onions in a microwave-safe container with a splash of water. Heat in 30-second increments, stirring each time, until heated through.
Not a fan of red onions? You can use this method/recipe to roast yellow onions as well.