Onion Soup

Creamy Onion Soup with Sage

This velvety, smooth and mild Onion Soup is the perfect autumn or winter comfort food. It is very different from a traditional French Onion Soup which consists of pieces of onion in a thin, strongly-flavoured broth. I add a gentle hint of sage to my soup which adds an extra dimension to the flavour.

The idea for this soup came to me when I was making an onion sauce. I made a white sauce, containing soft pieces of onion, to serve with some Chestnut and Mushroom Pies. It occurred to me that the mild-but-tasty sauce would make a brilliant soup. I thinned it out a bit and blended it smooth and found out that it did!

I now make this soup regularly. It is one of those brilliant, simple recipes where very basic ingredients produce something wonderful with very little effort.

What you need to know about this Onion Soup recipe

  • The key to this recipe is to cook the onions on a low heat for twenty minutes to ensure that they become soft and sweet. This process (step 2) is transformational and gives the finished soup a real depth of flavour and sweetness.
  • Try and use a good quality stock (step 4) as this will also make a big difference to the flavour. If you have home-made stock, so much the better. However, I generally use good quality vegetable bouillon powder.
  • My version of this soup is vegetarian. However, it is very easy to make the recipe vegan by using vegetable oil instead of butter (step 1) and by using a non-dairy milk (coconut milk or a nut milk such as almond or cashew) (step 6).
  • This soup can be made in advance and then reheated. It also freezes well and can be kept in the freezer for at least 6 months.

Other easy vegetarian soup recipes

I have lots of easy, vegetarian soup recipes. If you like this Onion Soup you might like some of the others. All my soups are vegetarian and all can be made vegan by substituting animal fats, such as butter, for vegetable fats. Some of them are pretty simple such as Leek and Potato Soup, Nettle Soup, Fennel SoupJerusalem Artichoke Soup  or Sweetcorn Chowder and showcase a single vegetable.

Others combine vegetables which have complimentary flavours such as Curried Parsnip and Apple SoupMoroccan Spiced Sweet Potato SoupCeleriac and Apple SoupMushroom and Chestnut SoupPumpkin and Sweetcorn Soup or Leek and Potato Soup. A few have more unusual combinations of flavours such as Beetroot Soup with Coconut or Butternut and Peanut Butter Soup. I also have a few chilled soup recipes, which are fantastic cold in the summer, but can also be served warm such as Asparagus and Pea and Tomato.

Recipe for Creamy Onion Soup with Sage

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Onion Soup with Sage

  • Author: Tastebotanical
  • Prep Time: 10
  • Cook Time: 30
  • Total Time: 40 minutes
  • Yield: Serves 6
  • Category: Soup
  • Cuisine: English


This mild and velvety Onion Soup, gently flavoured with sage, is easy to make and is the perfect comfort food.


  • 75 g (3 oz) butter or oil
  • 5 large onions
  • 2 teaspoons chopped fresh sage or 1 teaspoon dried sage
  • Salt and Pepper
  • 50 g (2 oz) plain flour
  • 600 ml (1 pint) vegetable stock
  • 300 ml (Half a pint) of milk, vegetable stock or water


  1. Heat the butter or oil in a heavy-based pan. 
  2. Peel and slice the onions.  Add to the pan with the sage, season with salt and pepper and cook slowly for twenty minutes until they are soft and sweet. 
  3. Add the flour and cook for a further two minutes. 
  4. Add the 500 ml of vegetable stock and simmer for a further 10 minutes.
  5. Blend the soup until smooth using a hand blender or food processor.
  6. Add up to 300 ml of milk, vegetable stock or water to thin the soup to your desired consistency. 


Keywords: soup, onion soup, onion, vegetarian

This recipe has been shared on #CookBlogShare with Lost in Food and #FiestaFriday with Fiesta Friday and   Liz@Spades, Spatulas & Spoons 


6 thoughts on “Onion Soup”

  1. I’m a huge fan of creamy onion soup but I automatically reach for the thyme. I’ll def be grabbing some sage next time – the combo sounds delish!

    1. Thank you! Homemade soup is such a good lunch option at this time of year (or anytime actually 😊)

  2. Delicious sounding soup, a love sage at this time of year and sage and onion is such a great combination. Thanks for linking up to #CookBlogShare. Michelle

    1. Thank you! I love sage and onion. It reminds me of my mum’s Sunday dinners when I was growing up!

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