Slow Cooker Leek and Potato Soup

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Slow Cooker Leek and Potato Soup is an easy to make super satisfying, cosy comfort food in a bowl. Perfect for a delicious lunch or serve with homemade bread for a winter warming dinner.

Using only 5 basic ingredients you can have the most delicious Slow Cooker Creamy Leek and Potato Soup.

Prepared like a regular soup but can be left slow cooking for the morning so it’s ready for lunchtime – it really is that easy.

Leeks and onion are gently sautéed in butter and then cooked with potatoes and stock. Finished with a quick blending and seasoning at the end. Or if pushed for time, skip the sauté stage and simply add all the ingredients and leave to cook.

I make my Slow Cooker Leek and Potato Soup without cream. Instead I use a small amount of milk and 50 grams of butter. I find this adds enough rich creaminess without masses of added calories.

Here at the Kitchen Shed our slow cooker is nearly always in use and it really does earn its keep. Be it a hearty beef stew and dumplings or a vegetable and bean casserole, the slow cooker comes in to its own. But I must admit, a satisfying bowl of Slow Cooker Leek and Potato Soup takes some beating.

What equipment do I need ?

• 4 to 6 person slow cooker – I used my 4.7 litre Crock Pot
• Shallow sauté pan – optional for softening the leeks and onions in butter first.
• Immersion or stick blender

What ingredients do I need ?

Minimal pantry ingredients deliver maximum flavour. With only 5 ingredients you can make the most delicious irresistible Slow Cooker Leek and Potato Soup.

• Leeks – leeks are the star of the show so I’ve used 4 large leeks.
• Onion – I used one brown onion.
• Salted butter – you only need 50 grams to gently sauté the leeks and bring out their buttery sweet flavour.
• Potatoes – I used Maris Piper potatoes but any floury potato variety such as Russet works really well. You only need 3 small potatoes, just enough to give the soup a classic creamy finish.
• Vegetable stock – I used Marigold stock granules. Alternatively, use a well flavoured chicken stock. I tend to cook with vegetable stock as I prefer a meat free soup.
• Optional: milk – adds a creamy finish to the soup without the extra calories of cream.
• Seasoning – there is already salt in the butter and seasoning in the stock so it’s best to add at the end according to your taste.

How to make Slow Cooker Leek and Potato Soup

Prepare Vegetables:

• Clean and trim your leeks. Discard the outer leaves, trim off the root end and the top dark green part of the leek but keep the light green part.
• Slice each leek lengthways and wash them under cold running water to remove any dirt or grit.
• Slice across the leeks to give half moons.
• Peel and dice onion.
• Peel potatoes and cut in half before slicing thinly.

Two step method:

• Add sliced leeks and onion to slow cooker and dot with cubes of butter. Cook on high for a couple of hours.
• There is the option to initially cook the leeks and onion before adding them to your slow cooker:
• Heat butter in a large sauté pan over a medium heat before adding sliced leeks and diced onion. Cook, stirring occasionally, for 10 minutes or until softened. Add to your slow cooker.
• Add sliced potatoes and stock to the softened leeks and onion.

• Cook on high for 3 hours or low for 6 hours.
• Check the potatoes are nice and soft before whizzing with an immersion blender. Do not over process or you will end up with a gluey soup.
• Add milk if using and season to taste.

All in one method:

Add all ingredients to the slow cooker except for the milk and seasoning.
Cover with the lid and cook on low for 8 hours or on high for 4 hours.
Blend and add milk if using to finish the soup. Check for seasoning.

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Slow Cooker Leek and Potato Soup

Slow Cooker Leek and Potato Soup is an easy to make super satisfying, cosy comfort food in a bowl. Perfect for a delicious lunch or serve with homemade bread for a winter warming dinner.

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5 from 32 votes

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Course: Lunch, Main, Soup, Starter

Cuisine: French

Prep Time: 15 minutes

Cook Time: 4 hours

Total Time: 4 hours 15 minutes

Servings: 6

Calories: 201kcal

Author: Sarah James

Equipment

• 4 to 6 person slow cooker – I used my 4.7 litre Crock Pot
• Shallow sauté pan – optional – to soften the leeks and onion in butter on the stove top
• Immersion / stick blender

Ingredients

• 4 large leeks
• 1 onion – diced
• 50 g salted butter
• 3 medium floury potatoes I used Maris Piper
• 750 ml vegetable or chicken stock I used Marigold granules
• Black pepper to taste
• Salt to taste

Optional

• 250 ml milk
• Freshly chopped parsley
• Croutons

MetricUS Customary

1x2x3x

Instructions

Prepare the vegetables

• Clean and trim your leeks by discarding the outer leaves before trimming off the root ends. Now cut off the thicker top dark green parts but leave the lighter green parts.
• Slice each leek lengthways in half and then wash them under cold running water to remove any dirt or grit.
• Slice across each leek to give approximately equally sized half moons.
• Peel and dice onion.
• Peel potatoes and cut in half before slicing thinly.

Two Step Method

• Add sliced leeks and onion to slow cooker and dot with cubes of butter. Place on lid and cook for 2 hours on high setting.
• Add sliced potatoes and stock.
• Replace lid and cook for 3 hours on high setting or 6 hours on low setting.
• Blend the soup until smooth using an immersion / stick blender. Do not over blend or you will end up with a ‘gluey’ soup.
• If using milk for a creamier soup, stir it in before seasoning to taste with salt and pepper.
• Alternatively, sauté leeks and onion in butter until soft using a shallow stove top pan before adding to slow cooker.

All in one Method:

• Add all ingredients to the slow cooker except for the milk, salt and pepper.
• Cook with the lid for 8 hours on low setting or 4 hours on high setting.
• Blend the soup until smooth using an immersion / stick blender. Do not over blend or you will end up with a ‘gluey’ soup.
• If using milk for a creamier soup, stir it in before seasoning to taste with salt and pepper.
• Ladle into bowls and garnish with parsley and crusty croutons.
• Serve with homemade bread for a complete meal.

Notes

• Serves 6 as a side or 4 as a main course – calories are calculated for 6 servings.
• Slow Cooker Leek and Potato Soup in an airtight container will keep for up to 5 days in the fridge. Reheat thoroughly in the microwave or on the stove top.
• Freeze your leek and potato soup in a freezer proof container for up to 6 months.
• Nutrition information is approximate and meant as a guideline only.

Calories: 201kcal | Carbohydrates: 29g | Protein: 4g | Fat: 8g | Saturated Fat: 5g | Polyunsaturated Fat: 0.4g | Monounsaturated Fat: 2g | Trans Fat: 0.3g | Cholesterol: 23mg | Sodium: 584mg | Potassium: 558mg | Fiber: 3g | Sugar: 7g | Vitamin A: 1533IU | Vitamin C: 25mg | Calcium: 104mg | Iron: 2mg