Bubble & Squeak Recipe Baked with Red Onions

Bubble and squeak as a recipe couldn’t be simpler – and you don’t have to shape it into fishcake shapes and fry it!

Serve Bubble Squeak Baked Red Onion

This bubble and squeak recipe has red onions added to the mix and then it’s baked.  I’ve used my toaster oven to bake it, which is more fuel-efficient than a regular oven.  Many people will be cooking this as a side-dish, possibly Christmas leftovers, but, for me, just bubble and squeak was my lunch – served with a dollop of caramelised red onion chutney on the side 🙂

I had already made the mashed potato yesterday and I used frozen brussels sprouts from the freezer and some of the frozen red onions I’d put in the freezer earlier in the month.


  • 350 grams mashed potato
  • 175 grams of brussels sprouts
  • 40-50 grams of red onion, that’s about half an onion
  • Salt & pepper to season, optional
  • Knob of butter, optional
  • Oil for oiling the baking dish

Note: These amounts aren’t fixed.  When you make a bubble & squeak you really use what you’ve got and how it looks to you, by eye.  The recipe does not rely on precise weights!


  1. I defrosted the frozen brussels sprouts in the microwave in a dish of water for just 3 minutes.  If your brussels are raw, then cook them for 5 minutes; if your brussels sprouts are large, cut them in half before you cook them for 5 minutes.  Chop up the brussels sprouts to the size that appeals to you.
  2. Cut up the red onion to the size you want it to be.  I’d frozen sliced red onions, but wanted them smaller in the bubble & squeak, so I just cut them smaller – done while the onions are frozen this takes just a few seconds.
    Bubble Squeak Recipe Baked Red Onion
  3. Combine the potato, brussels sprouts and red onion – it’s up to you whether you pulverise the mix into a smooth paste, or leave it quite chunky.  Personally, I prefer mine chunky, but it’s entirely your choice, so combine, mash, mix the three ingredients together until you like the look of it.  If the potato is firm enough it won’t need any further “binding”, you can add in a knob of butter if you wish, I usually don’t.  If your potato is a little sloppy and loose then you can firm it up by adding in some dried potato powder if you’ve got it.  I don’t use any milk in making my mash in the first instance, so it’s never sloppy.
    Bubble Squeak Baked Red Onion
  4. Season with salt and pepper if you wish and mix that in.
  5. Oil a small baking dish, so the mix doesn’t stick.  What I tend to do is to line my dish with foil and oil the foil, but that’s just me.
  6. Spoon the mixture into your baking dish and press it down hard.  Smooth the top off, or make a pretty pattern, it’s up to you.  I like the top to be a little “roughed up” as I prefer how that looks.
    Recipe Baked Bubble Squeak
  7. Now simply bake your bubble & squeak in a pre-heated oven at 200°C (19°0C fan oven) for 20-25 minutes until it “looks nice” to you.  What’s in the dish is already cooked and 20 minutes is just simply reheating all those ingredients.
    Toaster Oven: If you’re cooking this is a toaster oven, then there’s no need for pre-heating, just place the dish on the bottom shelf, turn the top and bottom elements on, set the temperature to 200°C and set the timer for 20 minutes.
  8. Serve when you like the look of it!  As a side dish just serve yourself a portion, as a standalone dish, add a dollop of nice chutney or even tomato ketchup on the side.  A quick splash of balsamic vinegar over the top is nice too!

Baked Bubble Squeak Toaster Oven

You don’t have to stick to this basic recipe, you can use white/yellow onions if you wish, or even top the top with a layer of grated cheese.  Adding a good layer of caramelised onion chutney half way through spooning the mix into the dish can produce great results too, as can a layer of grated cheese to give you a nice cheesy filling.


Q: Can I make this quicker?

A: Once you have the mixture combined, you can microwave it until it’s hot (4-5 minutes), then put into a baking dish and brown it off under the grill for 3-4 minutes.  Same great result, faster.

Q: How long will this keep in the fridge?

A: Once cooked, if you’re not going to eat it right now, or you have leftovers, simply wrap the leftovers in foil, or in a plastic lidded box in the fridge and it’s fine for 4-5 days.  It’s just vegetables!
I use takeaway boxes:
Leftovers Bubble Squeak Baked Onion

Q: Can I freeze bubble & squeak?

A: Yes, you can.  You can freeze it before you’ve baked it, or freeze it once it’s been baked and cooled.  It’s best defrosted in the fridge overnight, then you can microwave it hot again (3 minutes) or bake it again (15-20 minutes).

Enjoy this great sidedish that’s stuffed full of vegetables, giving you one of your 5-a-day and that’s really tasty.