Preheat the oven to 400°F. Wash and dry the fresh produce. Cut the potatoes into 1-inch-wide wedges. Thinly slice the mushrooms. Halve, peel, and thinly slice the onion(s).

Transfer the potato wedges to a sheet pan. Drizzle with olive oil and season with salt and pepper; toss to coat. Arrange in an even layer. Roast 22 to 26 minutes, or until browned and tender when pierced with a fork. Remove from the oven.

In a medium nonstick pan (or large for 4 servings), heat a drizzle of olive oil on medium-high until hot. Add the sliced mushrooms in an even layer. Cook, without stirring, 3 to 4 minutes, or until lightly browned. Add the sliced onion(s); season with salt and pepper. Cook, stirring occasionally, 3 to 4 minutes, or until softened. Turn off the heat.

Crack the eggs into a large bowl; beat until smooth. Add the fontina, crème fraîche, and as much of the truffle zest as you'd like. Whisk until thoroughly combined and smooth. Add the cooked mushrooms and onion(s). Season with salt and pepper; stir to combine.

Place the pie crusts on a separate sheet pan, leaving them in their tins. Evenly divide the filling between the crusts; season with salt and pepper. Bake, rotating the sheet pan halfway through, 19 to 21 minutes, or until the crusts are lightly browned and the filling is set and cooked through. Remove from the oven. Let stand at least 2 minutes before serving. Serve the baked quiches with the roasted potato wedges. Enjoy!