Recipe: Sweet Potato, Red Onion, Spinach & Feta Quiche

Sweet Potato, Red Onion, Spinach & Feta Quiche #picnic #summer #quiche

This post was created in partnership with Appletiser. Those of you who listened to Nigella Lawson on the Eater Upsell podcast the other day will have been reminded of the fridge forage; something I preach whenever I’m asked about how to cut down on food waste (an increasingly salient question on a topic I’m obsessive about, without ever actually sharing much). It is something we should be doing with all of our leftover veggies, not just to help the environment, but to save money, too. I went through a phase of turning everything into a pasta sauce, and then a breakfast frittata. At the moment, I’m all about using my leftovers to fill a good quiche, slices of which, incidentally are excellent for warm weather picnicking. So, enter stage right a reproduction of something I made for dinner the other week to use up the odds and ends from several recipes lurking in the fridge: my Sweet Potato, Red Onion, Spinach & Feta Quiche.
Appletiser Picnic Basket #picnic #summer
As regular readers will know, this year I have teamed up with Appletiser to bring you a new recipe every month that manages to pack in a whole extra portion of fruit and veg for your day with no added sugar, just like a glass of Appletiser. In case by the time this post has gone live it is no longer sunny, and we’re experiencing wall to wall thunderstorms until late September (this is Britain after all!) you have two options. Either serve this quiche up with a side salad on regular plates indoors. Or, check out some of the other recipes I’ve created to pair with Appletiser this year: Spiced Aubergine with Barley, Yogurt & Pomegranate, Pea & Mint Crusted Salmon with Brown Rice and Crispy Kale, Pasta with Spring Greens & Fresh Spinach Pesto.

Summer Picnic with Appletiser #picnic #summer #quiche
I think people go to too much fuss over picnics in general, getting too many bits and pieces. This is fine if you’re going to a deli or somewhere (though doing things that way can get pricey!), but if you want to do a homemade picnic, I try to focus on just making one or two things, then buying in some fresh fruits and veggies to crunch on. Appletiser is the perfect pairing for a picnic as the little bottles are the perfect size to portion things out so you don’t need to get glasses which  might break en-route (I hate drinking out of those horrid plastic ones!) Luckily there is no booze in Appletiser that would exclude whoever drove you out to your beautiful, secluded spot (read: people who don’t live in London!)

I teamed up with Appletiser again on my picnic post last year (is this going to become a tradition?) and again there I made sure my offering was simple: my Easy Apricot & Almond Sausage Rolls, my go-to potato salad recipe I can basically make with my eyes shut, and some baby, crunchy veggies to nibble on. Here, as all your crunchy/ veggie/ creamy/ savoury needs are met in each quivering slice of quiche, so just pick up a punnet of early to new season, local strawberries, and you’re all set.
Sweet Potato, Red Onion, Spinach and Feta Quiche #quiche #picnic #feta #summer #sweetpotato #spinach
Slice of Sweet Potato, Red Onion, Spinach & Feta Quiche #picnic #summer #quiche

As this quiche was, after all, something I came up with to clear the fridge, it is clearly very versatile. Any roasted squash or root veggies can be used instead of the sweet potato, and you’ll still get a beautiful sweet, caramelised bite from the onions if you have to use white ones instead. If you don’t have any feta, while goats cheese will give the quiche a totally different character, it will retain that creaminess where it melts into the egg mixture while it is cooking. One quiche should serve 6-8 people.

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Sweet Potato, Red Onion, Spinach & Feta Quiche

  • Author: Rachel Phipps
  • Prep Time: 20 minutes
  • Cook Time: 1 hour
  • Total Time: 1 hour 20 minutes
  • Yield: Serves 6-8 1x
  • Cuisine: French


This easy quiche recipe loaded up with sweet, caramelised red onion, sweet potato, spinach and feta quiche is delicious warm, or cold and packed up for a picnic.


  • 1 x 500g (18 oz) Pack Shortcrust Pastry
  • Plain Flour
  • Unsalted Butter, at room temperature 
  • 1 Very Small Sweet Potato, peeled and cubed
  • Light Olive Oil
  • 1 Large or 2 Small Red Onions, thinly sliced
  • 2 Large Handfuls Baby Spinach
  • 100g (3.50 oz) Feta, crumbled
  • 2 Large Egg Yolks
  • 2 Large Eggs
  • 50ml (2 fl oz) Whole Milk
  • 1 x 150ml (5 fl oz) Pot Single Cream
  • Freshly Ground Sea Salt and Black Pepper


  1. Pre-heat the oven to 200 degrees (400 Fahrenheit) and place a metal baking sheet in the oven to heat up. By baking the quiche on this, you’ll avoid a soggy bottom without any need to blind bake.
  2. Roll the pastry out on a floured surface to the thickness of your average quiche crust. Grease your quiche dish well with butter (this will also help crisp the pastry to avoid a soggy bottom). Using the rolling pin to help support the pastry, lift it up over the dish and press it into the edges. Use a sharp knife to tidy up the edges, and chill the case in the fridge while you’re making the fillings. You can make jam tarts out of the scraps!
  3. Cook the sweet potato cubes in a pan of cold, salted water until they are just tender. Drain well, and set aside spread across a plate lined with kitchen paper to cool.
  4. Cook the onions in a large frying pan with a glug of light oil and a pinch of salt over a medium low heat until they are soft and starting to caramelise.
  5. Gradually stir in the spinach until it has wilted and most of the liquid has evaporated. Remove the pan from the heat.
  6. To make the quiche filling, whisk together the egg yolks, egg, milk and cream until combined, along with a generous amount of salt and pepper.
  7. To assemble the quiche, spread the onion and spinach mixture across the bottom of the chilled pastry case. Sprinkle over the sweet potato cubes and the feta, and pour over the egg and cream mixture.
  8. Bake for 40-45 minutes until the pastry is crisp and golden, and the egg mixture is set and just starting to brown.
  9. If serving warm, at home, leave it for 10 minutes to stand before cutting into it. Allow it to cool completely before slicing for a picnic and wrapping in greaseproof paper (along with your local strawberries and fridge cold bottles of Appletiser!); the pastry will go soggy if you wrap it in foil!

A few ideas for a weekend/ after work picnic during some of the warm summer days and nights ahead: Super Simple 3-Step Chocolate Brownies, Asian Butterbean Salad, Mini Marinated Mozzarella in a Jar, Salted Caramel Double Chocolate Rolo Cookies, Summertime Spinach, Bacon & Quark Quiche, A Cheap & Easy Classic Tea Bread, A Classic Quiche LorraineA Traditional French Pissaladière, Homemade HoneycombGiant (Israeli) Couscous with Pomegranate & Pistachios, Strawberry Buttercream & Pistachio Mini Cakes, Classic & Easy Summer Mini Crayfish Rolls, Easy Black Bean & Sunflower Seed Dip, Vietnamese Steak Salad Summer RollsOrange Glazed Cacao Mini Baked Doughnuts.

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