Jersey Royal Potato and Asparagus Tart with Hollandaise Sauce

**Prepare the Tart Base:** Preheat oven to 180°C (160°C Fan/Gas Mark 4). Roll out the shortcrust pastry on a lightly floured surface and use it to line a 9-inch tart tin with a removable bottom. Prick the base all over with a fork. Line the pastry with baking parchment and fill with baking beans or rice.

**Blind Bake:** Bake for 15 minutes, then remove the baking beans and parchment and bake for a further 5-10 minutes, or until the pastry is pale golden and cooked through. Set aside to cool slightly.

**Cook the Potatoes:** While the pastry is baking, boil the Jersey Royal potatoes in salted water until tender, about 15-20 minutes. Drain well and allow to cool slightly. Once cool enough to handle, slice the potatoes into 1/2 cm thick rounds.

**Sauté Vegetables:** Heat the olive oil in a large pan over medium heat. Add the sliced spring onions and sauté for 2-3 minutes until softened. Add the sliced Jersey Royal potatoes and sauté for another 5 minutes, gently tossing them until they are slightly golden.

**Prepare the Asparagus:** Blanch the asparagus spears in boiling water for 2-3 minutes until bright green and slightly tender-crisp. Drain well and pat dry.

**Assemble the Tart:** Arrange the sautéed potato mixture evenly in the baked tart base. Top with the blanched asparagus spears, arranging them in a decorative pattern.

**Make the Hollandaise Sauce:** Place the egg yolks and Jersey milk in a heatproof bowl set over a pan of simmering water (or use a double boiler), making sure the bottom of the bowl doesn't touch the water. Whisk constantly until the mixture becomes pale and thickens slightly.

**Emulsify the Hollandaise:** Gradually whisk in the cubed Jersey butter, a few cubes at a time, until fully incorporated and the sauce is smooth and glossy. Remove from the heat and whisk in the lemon juice and a pinch of cayenne pepper (if using). Season to taste with sea salt and black pepper.

**Dress the Tart:** Pour the hollandaise sauce evenly over the potato and asparagus tart.

**Garnish and Serve:** Sprinkle the tart with chopped fresh mint. Serve immediately.