Dinner

Mustardy Roast Potatoes Recipe

ByNoah Steele February 5, 2026February 5, 2026

Introduction

These mustardy roast potatoes are a crispy, flavorful twist on a classic favorite. Coated in a tangy wholegrain mustard glaze and roasted to golden perfection, they make an irresistible side dish for any meal. Serve them with salt beef and gherkins for a deliciously satisfying experience.

A close-up top view of a round white bowl filled with golden-brown roasted potato chunks, each piece coated in whole grain mustard seeds and sprinkled with coarse sea salt, showing crispy, textured edges and soft, fluffy insides. The potatoes have a light yellow center with a crunchy outer layer dotted with dark brown mustard grains. The bowl is placed on a purple cloth, with a white marbled surface underneath. Around the bowl, a sliced piece of pink roasted meat and some chopped green pickles are slightly visible. Photo taken with an iphone --ar 4:5 --v 7

Ingredients

1kg starchy potatoes (such as Maris Piper or King Edward), peeled and cut into large chunks
2 beef stock cubes

200ml neutral-tasting oil, such as vegetable
4 tbsp wholegrain mustard

Sweet & sour gherkins, to serve
Dijon mustard, to serve

Instructions

Step 1: Put the potatoes in a large saucepan. Cover with cold water and add 1 tbsp salt. Bring to the boil and crumble in the beef stock cubes. Reduce heat to a simmer and cook for 8-10 minutes until the potatoes are tender. Drain well.
Step 2: Shake the potatoes in the colander to rough up the edges, then leave them to steam-dry for at least 10 minutes for extra crispiness.
Step 3: Heat the oven to 220°C (200°C fan/gas mark 7). Pour the oil into a large roasting tin and place it in the oven to heat for at least 10 minutes until the oil is shimmering.

Step 4: Carefully tip the potatoes into the hot oil—the oil may spit. Roast for 40 minutes, turning once halfway through for even color.
Step 5: Mix the wholegrain mustard, 1 tbsp warm water, and a pinch of salt and pepper in a small bowl to create a loose glaze.
Step 6: After the initial 40 minutes, brush the mustard glaze all over the potatoes and pour any leftover glaze into the roasting tin. Roast for another 40 minutes until the potatoes are dark brown and crispy all over.

Step 7: Serve the potatoes warm with slices of salt beef, sweet & sour gherkins, and Dijon mustard for dunking. Buttered rye bread on the side is a great addition.

Tips & Variations

Using starchy potatoes helps achieve the perfect crispy texture on the outside and fluffy inside.
For extra flavor, add a few crushed garlic cloves or fresh rosemary to the roasting oil.

If you prefer a milder mustard kick, use Dijon mustard instead of wholegrain mustard in the glaze.
To ensure crispiness, avoid overcrowding the roasting tin so the potatoes roast evenly.

Storage

Store leftover roast potatoes in an airtight container in the refrigerator for up to 3 days. Reheat in a hot oven or air fryer to maintain crispiness rather than using a microwave, which can make them soggy.

How to Serve

A close-up of a round white bowl filled with golden roasted potato chunks, each piece showing a crispy, slightly browned texture with the surface sprinkled with grainy mustard seeds and coarse salt flakes, giving a rough, crunchy look. The potatoes have a warm yellow color with some edges darker from roasting. The bowl is placed on a wooden board with a purple cloth beneath it, and parts of sliced pink deli meat and bright green pickles are visible near the bowl on the white marbled surface. photo taken with an iphone --ar 4:5 --v 7

Serve this delicious recipe with your favorite sides.

FAQs

Can I use a different type of potato?

Starchy potatoes like Maris Piper or King Edward are best for roasting because they crisp up well. Waxy potatoes will be less crispy but can still work if that’s what you have.

Is the beef stock necessary?

The beef stock cubes add depth of flavor to the potatoes while boiling, but you can omit them for a vegetarian version or substitute with vegetable stock cubes.