Clean mushrooms by brushing or wiping with a damp paper towel; trim stems and slice larger mushrooms into bite-size pieces so all are roughly uniform.

Heat a large sauté pan over medium-high heat until hot. Add olive oil and butter. When butter foams, add mushrooms in a single layer (work in 1–2 batches if necessary to avoid steaming).

Cook, undisturbed for 2–3 minutes, then stir occasionally for another 3–4 minutes until edges brown and moisture is mostly evaporated.

Add minced garlic, minced shallot, and thyme. Sauté 30–60 seconds until aromatic, being careful not to burn the garlic.

Season with sea salt and freshly ground black pepper. Pour in 2 tablespoons dry sherry to deglaze the pan; scrape up any browned bits and cook 30–60 seconds to reduce liquid. Remove from heat and keep warm.

Truffle-Sherry Vinaigrette

In a small bowl or jar combine sherry vinegar, dry sherry, Dijon mustard, minced shallot, honey (if using), salt, and pepper. Whisk to combine.

Slowly whisk in extra-virgin olive oil in a steady stream until emulsified, or shake vigorously in a jar with a tight lid.

Stir in white truffle oil sparingly (about 1/2 teaspoon) and taste; adjust seasoning with salt, pepper, or a touch more vinegar or honey to balance acidity.

Assemble Tableside

Place 1 cup baby arugula in the center of each of four salad plates (serves 4). Arrange two endive half-heads per plate around the arugula and distribute halved tomatoes among the plates.

Lightly dress the arugula, endive, and tomatoes: drizzle about 1 tablespoon of the truffle-sherry vinaigrette over each plate and gently toss or fan the greens so they are evenly coated but not soggy.

Divide the warm sautéed mushrooms evenly among the four plates, placing them on top of and around the greens so their warmth slightly wilts the arugula and endive.

Using a vegetable peeler, shave Parmigiano-Reggiano over each salad (about 2 tablespoons per plate).

Finish each plate with very thin shavings of fresh black truffle (split the 1/2 oz across plates) or a light drizzle of additional truffle oil if fresh truffle is unavailable.

If desired, sprinkle a small pinch of coarse sea salt over each plate and grind a little extra black pepper. Serve immediately tableside so guests enjoy the aroma of warm mushrooms and truffle.