Mushroom tarte tatin

Method

1. Melt the butter in an ovenproof 24-26 cm skillet over medium-high heat. Add the mushroom wedges in a single layer, working in batches if the pan is crowded (crowding steams mushrooms instead of browning them, and you want brown here). Let them cook undisturbed for a few minutes until deeply browned on the cut sides, then toss and continue cooking until they’ve released their liquid, that liquid has boiled off, and the mushrooms look dry, shrunken, and caramelized rather than wet, 10-12 minutes total. If you worked in batches, return everything to the pan now.
2. Add the sliced shallots and garlic and cook for 2-3 minutes, stirring, until softened and fragrant but not coloured beyond pale gold. Season with the salt, pepper, and thyme leaves, and stir through.
3. Pour in the sherry vinegar. Let it bubble hard for 30-60 seconds, scraping up any browned bits from the base of the pan with a wooden spoon, until it’s almost entirely reduced away. Taste a mushroom, adjust the seasoning, and take the pan off the heat.
4. Press and spread the mushroom mixture into one even layer across the base of the pan, right to the edges, so the top of the tart (which will become the bottom once flipped) is level.
5. Lay the cold, pricked puff pastry round over the mushrooms. Tuck the edges down and slightly under, against the inside wall of the pan, so the pastry cups the filling rather than sitting flat on top.
6. Bake at 200°C (400°F) on a middle shelf until the pastry is deep golden brown and well-risen, 25-30 minutes.
7. Remove from the oven and let the tart rest in the pan for 5 minutes, this lets the juices settle so they don’t run everywhere on the flip. Run a thin knife around the inside edge of the pan to loosen the pastry, then invert a large plate over the pan and, holding both firmly together with oven gloves, flip in one confident motion. Lift the pan away carefully; if any mushrooms stick, just scoop them back into place.
8. While the tart is still warm, crumble the Gruyère or blue cheese over the top so it melts slightly into the mushrooms, and scatter over the parsley or extra thyme leaves. Slice and serve warm.

Notes

• Storage and reheating: keeps in the fridge, loosely covered, for up to 2 days. Reheat slices in a 180°C oven or air fryer for 8-10 minutes to recrisp the pastry; the microwave will make it soggy. Not a good candidate for freezing, the pastry base turns soft on thawing.
• Don’t crowd the mushrooms: this is the step that makes or breaks the tart. A skillet packed too full of mushroom wedges traps steam, and they’ll simmer in their own liquid instead of browning, giving a grey, wet filling that soaks the pastry. If your mushrooms don’t fit in one layer with a little breathing room, brown them in two batches and combine at the end.
• Mix your mushroom textures: an all-cremini tart works but tastes a little one-note. Pairing a softer, moisture-heavy mushroom like cremini or chestnut with a meatier, denser one like king trumpet or portobello gives a better range of texture, the dense ones hold their shape and chew after baking while the softer ones caramelize into something almost jammy at the edges.
• Gruyère AOP is traditionally made with animal rennet, so this isn’t strictly vegetarian as written. A vegetarian Alpine cheese, or an Emmentaler set with microbial rennet, is a good substitute that makes it vegetarian.

Ingredient substitutions

• Puff pastry: all-butter puff pastry is the traditional and clearly better choice here, it browns more deeply, tastes richer, and laminates more distinctly than pastry made with vegetable shortening. In Germany, the refrigerated Blätterteig from the chilled section (not the freezer) is usually all-butter already and is a good, easy default. In the US and Canada, most supermarket puff pastry (Pepperidge Farm included) is made with vegetable shortening, so look specifically for an all-butter brand like Dufour if you want the same result. Homemade rough puff pastry is a reasonable middle ground if you want to make your own without committing to full classic lamination, which offers little visible benefit here anyway since the pastry ends up as a flat lid rather than a laminated showpiece. Whatever pastry you use, it must go onto the filling cold, straight from the fridge, or it won’t puff properly and may shrink or slide as it bakes.
• Cheese: Gruyère gives a nutty, savory finish; a soft blue cheese (such as Gorgonzola dolce or a mild Roquefort) gives a sharper, creamier one. A firm, aged goat cheese also works well if you want something tangier than Gruyère but milder than blue.
• Vinegar: if you don’t have sherry vinegar, a good red wine vinegar or even a splash of dry white wine works, though sherry vinegar’s slight sweetness and nuttiness suits the caramelized mushrooms particularly well.

Sources consulted

• The Kitchn: Tomato Tarte Tatin