These slow roasted onions are an easy, flavourful, budget-friendly side dish that can be prepared in advance. They’re perfect for the holidays or whenever you’re craving some sweet, caramelized oniony goodness. This dish is gluten-free, vegan, and paleo diet-friendly.
Main ingredients & substitutions
You can use any type of onions you like for this recipe. Sweet onions or red onions are my top choices, but any variety will work.
Dried thyme gives these onions a lovely aroma and warm, cozy flavour. You can substitute dried rosemary instead if you prefer.
I used extra virgin olive oil in this dish but you can substitute any other neutral oil you prefer.
How to make them
These onions do take a while to make, but they’re really easy and can be prepared in advance, which makes them the perfect addition to a holiday feast or any other special occasion meal. These baked onions are a great, easier alternative to caramelized onions, which are traditionally made on the stovetop and require a lot of stirring and attention to ensure they don’t burn.
To make these roasted onions, start by preheating the oven to 300 degrees Fahrenheit, then roughly chop the onions.
Add the chopped onions, thyme, olive oil, salt, and pepper to a large baking dish (mine is 9 x 13 inches, but any similar size is fine). Use your hands or a spoon to toss the onions, ensuring they’re evenly coated with oil.
Bake at 350 degrees Fahrenheit for one hour, then mix thoroughly before continuing to bake for one additional hour or until the onions are golden brown around the edges.
Serve hot or store them in an airtight container in the fridge for up to three days, then reheat before serving.
Bell peppers are a delicious addition to this dish. Any colour is fine. Just remove the seeds and roughly chop the peppers, then add them to the baking dish along with the other ingredients.
What to serve them with
- Spoon some slow roasted onions over this easy, vegan baked polenta.
- They would also make a delicious filling for this vegan omelette made with chickpea flour.
- Or serve them alongside these stuffed portobello mushrooms.
Slow Roasted Onions
- 4 cups roughly chopped onions (any type of onion is fine)
- 2 tablespoons extra virgin olive oil
- 1/2 teaspoon dried thyme
- 1/8 teaspoon salt
- 1/8 teaspoon black pepper
- Preheat the oven to 300 degrees Fahrenheit.
- Roughly chop the onions.
- Add the chopped onions, extra virgin olive oil, dried thyme, salt, and pepper to a large baking dish (mine is 9 x 13 inches but any similar size is fine).
- Toss the ingredients with your hands or a spoon, ensuring that the onions are coated with oil.
- Bake at 300 degrees Fahrenheit for 1 hour, stir, then continue to bake for 1 additional hour or until they’re slightly golden brown around the edges.
- Serve these slow roasted onions hot or store them in an airtight container in the fridge for up to three days, then reheat before serving.