Asparagus, crispy potatoes and radishes with herb hollandaise

Method

1. Heat the oven to 200°C/180°C fan/gas 6. Put the potatoes in a pan, pour over boiling water to cover and boil for 7-8 minutes until not  quite tender. Drain, allow to steam dry for a couple of minutes, then press each one with a fork to squash it partially. Tip the potatoes into a large roasting tin, drizzle over the olive oil and toss to coat. Season with salt and pepper, then roast for 30-40 minutes until crisp, tossing occasionally so they brown evenly.
2. Around 20 minutes into the potatoes’ cooking time, make the hollandaise. Put the vinegar, shallots, mace and peppercorns into a saucepan with 6 tbsp water and bring to a rolling boil. Keep cooking until it has reduced to 2 tbsp liquid, then strain into a heatproof ceramic or glass bowl. Allow to cool slightly, then set the bowl over a pan of very gently simmering water (don’t let the water touch the bowl). Stir in the egg yolks along with a good pinch of salt.
3. Using a small whisk, beat the mixture together until frothy and well combined, then add a cube of the butter, straight from the fridge. Whisk to melt the butter before adding the next. Carry on adding one cube at a time and whisking before adding another. The mixture should thicken after the third or fourth cube. If it stays runny, keep whisking for a while before adding the next piece. If the mixture starts to develop a greasy sheen on top, add a small splash of cold water and whisk again.
4. Once you’ve added around two thirds of the butter and the sauce has thickened up, you can start adding a few chunks at a time. Once all the butter has been added, you should have a smooth sauce that thickly coats the back of a metal spoon. Turn off the heat, taste the hollandaise and add more salt or a squeeze of lemon juice if you think it needs it. It should taste slightly acidic, buttery and rounded. Cover with a piece of cling film touching the surface of the sauce, and leave the bowl sitting on top of the water (heat switched off) until ready to serve.
5. Cook the asparagus spears in a steamer or pan of boiling water for 4-5 minutes until just tender (thin ones for 4 minutes, fatter ones for 5 minutes). Drain or remove the aparagus from the steamer to dry.
6. To serve, toss the asparagus and radishes with the roast potatoes and season well. Tumble onto a platter. Stir the chopped herbs through the warm hollandaise, then dollop over the veg. Serve with crusty bread.