Keep beef cold. Trim any sinew and silver skin. Using a very sharp knife, finely dice the wagyu into small uniform pieces (about 1/8" to 1/4"). Place diced beef in a chilled bowl and return to fridge until ready to mix.

Mix aromatics and season

In a small bowl combine the minced shallot, chopped capers (or chopped dill pickles), finely diced dill pickles, snipped chives, toasted sesame seeds, lemon juice, olive oil, kosher salt and black pepper. Stir to blend.

Gently fold the aromatic mixture into the diced wagyu until evenly distributed. Taste and adjust seasoning — add more salt, pepper or a few drops of lemon juice if needed. Keep chilled until plating. Do not overwork the meat; mix just until combined.

Mac Sauce (creamy sesame-mayo sauce)

Combine mayonnaise, ketchup, sriracha, toasted sesame oil, sweet pickle relish, white wine vinegar, sugar and salt in a small bowl. Whisk until smooth and taste — adjust heat or sweetness to preference. Transfer to refrigerator until serving.

Grilled Baguette

Preheat a grill pan or skillet over medium-high heat. Brush baguette slices lightly with melted butter or olive oil on both sides.

Place slices in the pan in a single layer. Grill until golden brown and crisp, about 1–1.5 minutes per side, pressing gently with a spatula for even contact. Remove to a tray and immediately rub the cut side with the halved garlic clove for a subtle garlic note.

Assembly & Garnish

To serve, spoon a generous tablespoon of mac sauce onto each grilled baguette slice (or smear on the plate). Using a ring mold or two spoons, portion about 3–4 tablespoons (roughly 1/4 cup) of the wagyu tartare per serving onto plates or directly on baguette slices.

Sprinkle a tiny pinch of flaky sea salt and extra toasted sesame over the tartare. Add a few microgreens or baby arugula beside or on top for brightness.

Serve immediately so baguette stays crisp. Provide extra mac sauce on the side if desired.