Baked Onions
These baked onions in a creamy parmesan sauce has become our favorite side dish. It’s incredibly savory, rich and moreish making it the perfect side dish for fall/winter and the festive season.
Ingredients and Substitutions
I wanted to develop a super simple baked onions recipe that didn’t require too many fussy steps. A side dish that can be made with minimal effort but that delivers huge on flavor. I kept it simple by roasting the onions first until soft then pouring over a creamy sauce. You can forego the creamy sauce and roast the onions with balsamic vinegar, a drizzle of honey or maple syrup and a few cubes of butter. This will give it delicious French onion soup vibes.
- Onions. Use any onion you want. Yellow onions/brown onions are my go-to but red onions, vidalia onions, Spanish onions or shallots all work.
- Olive oil.
- Sea salt and black pepper.
- Heavy cream.
- Parmesan cheese. Use a vegetarian alternative if necessary.
- Fresh thyme. Other fresh herbs like sage, parsley and oregano are all delicious with onions.
- Fresh garlic cloves. Garlic powder can be substituted.
How to make baked onions
- Slice the onions into 1cm/½in slices. Place in a single layer in a baking dish then drizzle over a few tablespoons of olive oil and season with salt and pepper.
- Make the creamy sauce by stirring together cream, grated parmesan cheese, minced garlic, fresh thyme leaves, salt and pepper in a measuring jug or small bowl.
- Bake the onions for 20 minutes until they are tender and starting to brown. Carefully flip over the roasted onions then pour over the creamy sauce. Return to the oven and bake for another 10-15 minutes until golden brown then remove and serve.
Can I make this ahead?
Yes, the baked onions can be made a few hours in advance and kept at room temperature. Reheat in the oven before serving. Leftovers can be kept in an airtight container in the refrigerator or for up to 3 days and reheated before serving.
Serving Suggestions
Baked onions are the ultimate side dish for meaty mains like roast chicken, lamb or beef. It’s also fantastic with steak since it’s kind of a side dish and sauce all in one.
- Oven Roasted Whole Chicken
- Air Fryer Lamb Chops
- Garlic Rosemary Rump Roast
- Air Fryer Steak
Onion Recipes
Ingredients
- 2 lb (1kg) onions
- 2 tbsp olive oil
- 1 tsp salt
- 1 tsp pepper
- ¾ cup heavy cream
- ½ cup grated parmesan cheese
- 1 garlic clove minced
- 1 tsp fresh thyme leaves
- 1 tsp salt
- ½ tsp pepper
Instructions
- Preheat the oven to 350°F/180°C.
- Slice the onions into 1cm/½in slices.
- Place in a single layer in a baking dish then drizzle over a few tablespoons of olive oil and season with salt and pepper.
- Bake the onions for 20 minutes until they are tender and starting to brown.
- Make the creamy sauce by stirring together cream, grated parmesan cheese, minced garlic, fresh thyme leaves, salt and pepper in a measuring jug or small bowl.
- Carefully flip over the roasted onions then pour over the creamy sauce.
- Return to the oven and bake for another 10-15 minutes until golden brown then remove and serve.