Preheat and prep: Position a rack in the upper third of the oven and preheat to 220°C / 425°F. High heat is essential to produce a fast, dry roast that crisps potato edges without stewing them.

Parboil the potatoes: Bring a large pot of salted water to a boil. Add the halved or small-cut fingerling potatoes and simmer 8–10 minutes until they are just tender when pierced with a paring knife but not falling apart. Parboiling starts the cooking process so the interior becomes tender while the oven can focus on crisping the exterior.

Drain and rough-dry: Drain the potatoes in a colander and let steam-dry for 2–3 minutes; shake the colander to slightly rough the surface (this creates more surface area that will crisp in the oven). While still warm, transfer to a rimmed baking sheet.

Season and roast the potatoes: Toss the warm potatoes with 4 tbsp extra-virgin olive oil, the chopped rosemary, a good pinch of sea salt and several grinds of black pepper. Spread them cut-side down in a single layer so each potato touches the hot sheet — contact creates the Maillard crust. Roast 25–30 minutes, turning once halfway, until deep golden and crisp on the edges.

Start the ragout base while potatoes roast: In a large sauté pan or shallow Dutch oven, warm 1 tbsp olive oil (from the pantry) over medium heat. Add the thinly sliced shallot and a pinch of salt; sauté 3–4 minutes until softened and translucent. Cooking the shallot slowly draws out sweetness and builds the base flavor of the ragout.

Add garlic and toast briefly: Add the minced garlic and the red-pepper flakes and sauté 30–45 seconds until fragrant. Toasting the garlic briefly (don't let it brown) releases its aroma and infuses the oil without turning bitter.

Concentrate the tomatoes: Add the halved cherry tomatoes to the pan and increase heat to medium-high. Cook, stirring occasionally, 6–8 minutes until many tomatoes begin to collapse and release juices — this concentrates sweetness and creates a naturally tangy sauce while keeping some whole tomatoes for texture.

Fold in the beans: Add the drained cannellini beans and gently stir to combine. Allow them to warm through and gently break up a few with the back of a spoon to thicken the ragout slightly; intact beans provide creamy texture while a few mashed ones act as a natural thickener.

Adjust liquid and seasoning: If the ragout looks dry, add 2–3 tbsp of water (or reserved bean liquid if you have it) to loosen the mixture; simmer gently 2–3 minutes. Stir in the lemon juice, taste, and season with sea salt and black pepper. Lemon brightens and balances the beans and tomatoes.

Wilt the spinach and finish: Add the baby spinach in handfuls, stirring until wilted (about 1–2 minutes). Remove the pan from heat and stir in most of the chopped parsley, reserving a tablespoon for garnish. Finish with grated lemon zest and the 2 tsp of good-quality extra-virgin olive oil for a glossy, aromatic lift.

Rest and plate: When the potatoes are crisp, remove from oven and season briefly to taste. Spoon a generous portion of the warm bean-and-tomato ragout over a bed of crispy potatoes on each plate. Scatter remaining parsley, a small extra drizzle of olive oil, and a final pinch of lemon zest and cracked black pepper.

Serve: Serve immediately so the contrast between hot creamy ragout and crunchy potatoes is at its best. Offer lemon wedges at the table for extra brightness.