White Mushroom “French Onion” Pizza

Ingredients

• Pizza dough for one 12-inch pizza (about 9–10 oz / 255–285 g), at room temp
• All-purpose flour or semolina, for stretching/dusting
• 1 cup (225 g) whole-milk ricotta
• 2 Tbsp (30 g) sour cream
• 1 small garlic clove, finely grated
• 1/2 tsp kosher salt, plus more to taste
• Freshly ground black pepper
• 1 Tbsp olive oil (or 1 Tbsp butter + 1 tsp oil), for onions
• 1 large yellow onion, thinly sliced
• 1/4 tsp kosher salt (for onions)
• 8–12 oz (225–340 g) cremini or button mushrooms, sliced
• 1 Tbsp olive oil, for mushrooms
• 2 cups (about 8 oz / 225 g) low-moisture mozzarella, shredded
• 2 Tbsp (10–15 g) finely grated Parmesan or Pecorino (optional but recommended)
• 1/2–1 tsp fresh thyme leaves (or 1/4 tsp dried thyme), optional
• To finish: 1–2 tsp fresh lemon juice OR lime juice (optional but recommended)

Instructions

1. Caramelize the onions: Heat a skillet over medium with the olive oil (or butter/oil). Add the sliced onion and 1/4 tsp salt. Cook, stirring every few minutes, until the onions are deep golden, sweet-smelling, and jammy—not just translucent—about 15–25 minutes. If the pan gets too dark, splash in 1–2 Tbsp water and scrape up the fond.
2. Brown the mushrooms: In a second skillet (or the same skillet wiped out), heat 1 Tbsp olive oil over medium-high. Add mushrooms in as even a layer as you can and cook until they release their liquid, then keep cooking until that liquid evaporates and the mushrooms re-brown and look drier, 8–12 minutes. Season with a pinch of salt and plenty of black pepper. Cool toppings on a plate so they don’t steam.
3. Heat the oven: Place a pizza stone/steel on the middle rack and preheat to 500–550°F (260–290°C) for at least 45 minutes. If using a sheet pan, preheat the oven fully; you’ll bake on the pan instead.
4. Mix the ricotta base: In a bowl, stir ricotta, sour cream, grated garlic, 1/2 tsp salt, and lots of black pepper until smooth and spreadable. If it feels stiff, loosen with 1–2 tsp water.
5. Stretch the dough: On a floured surface, stretch dough to a 12-inch round. Transfer to a floured peel (or parchment on the back of a sheet pan).
6. Top: Spread a thin, even layer of ricotta base, leaving a 1/2–3/4 inch rim. Sprinkle on about 2/3 of the mozzarella. Scatter on jammy onions and browned mushrooms (avoid piling them in wet clumps). Add remaining mozzarella and the Parmesan/Pecorino if using. Finish with thyme if using.
7. Bake until blistered and crisp: Slide onto the hot stone/steel and bake until the crust is deeply browned at the edges, the cheese is bubbling with golden spots, and the bottom feels crisp and firm when lifted with a peel—about 7–11 minutes depending on oven heat.
8. Brighten: Let the pizza rest 1–2 minutes, then hit it with 1–2 tsp lemon or lime juice (just enough to lift the richness). Slice and serve hot.

Notes

Make-ahead: Caramelize onions and brown mushrooms up to 2 days ahead; refrigerate, then bring to room temp or rewarm briefly and let steam off before topping. Sheet-pan method: Bake on a preheated inverted sheet pan or in a cast-iron skillet; expect 10–14 minutes at 500°F and a slightly softer bottom than stone/steel. Cheese note: Low-moisture mozzarella keeps the pie drier; if using fresh mozzarella, slice and blot very well. Finish note: The tiny hit of citrus is optional but highly recommended—it makes the flavors taste brighter and less heavy.