Leek and Potato Soup with Caerphilly

By AislePrompt Editorial · Published 2026-10-11 · Updated 2026-10-11

A velvety leek and potato soup simmered in vegetable stock and topped with crumbled Caerphilly and crisp fried leek ribbons. This Welsh-inspired soup recipe (vegetarian), ready in about 50 minutes, pairs floury potatoes, peeled and diced, onion, chopped, butter for a weeknight-friendly dinner that comes together with one pan and minimal cleanup. Each serving lands at about 260 calories and feeds 6, so it slots cleanly into a weekly meal plan and pairs well with a quick salad or grain on the side. Tap "Plan a meal with the AI" below to drop this recipe into your week and send the ingredients straight to Instacart. Nutrition values are approximate, calculated from USDA FoodData Central (fdc.nal.usda.gov) — verify against ingredient labels for any health-driven dietary plan.

Ingredients

• 4 leeks, sliced (plus 1 extra for garnish)
• 600 g floury potatoes, peeled and diced
• 1 onion, chopped
• 40 g butter
• 1.2 litres vegetable stock
• 200 ml whole milk
• 1 bay leaf
• 100 g Caerphilly cheese, crumbled
• 2 tbsp sunflower oil
• to taste white pepper and salt

The stock pot we’d simmer this in → Best Stock Pots for 2026: Top Picks + Buying Guide

Instructions

1. Step 1: Melt the butter and sweat the onion and sliced leeks over a low heat for 10 minutes without letting them brown.
2. Step 2: Add the potatoes, stock and bay leaf. Simmer for 20 minutes, until the potatoes are soft.
3. Step 3: Take out the bay leaf, add the milk and blend until smooth. Season with salt and white pepper.
4. Step 4: Cut the extra leek into thin strips and fry in the oil until crisp.
5. Step 5: Ladle the soup into bowls and top with the Caerphilly and crispy leeks.