Bring mixture to a gentle simmer over medium heat. Reduce heat to maintain a low simmer and cook, stirring occasionally, until mixture reduces to about 1/3 cup and coats the back of a spoon, 12–18 minutes (time varies by pan).

Remove from heat and allow to cool — glaze will thicken further as it cools. Transfer to a small jar or bowl and set aside at room temperature.

Salad assembly

Prepare tomatoes

While glaze reduces, rinse and dry heirloom tomatoes. Cut larger tomatoes into 1/2-inch wedges; slice small ones in half. Place on a cutting board and gently season with 1/2 teaspoon sea salt and 1/2 teaspoon freshly ground black pepper.

Dress arugula

In a medium bowl, combine 4 cups baby arugula with 2 tablespoons extra-virgin olive oil and the juice of half a lemon (about 1 tablespoon). Toss gently to coat. Taste and adjust with a pinch more salt or lemon if desired.

Warm burrata (optional)

If you prefer burrata slightly room temperature or slightly warm, remove from refrigerator 20 minutes before serving. For a lightly warmed center, place sealed burrata (in wrapper or in a heat-safe bowl covered) in 120°F (low) oven for 5–7 minutes; otherwise serve at room temperature.

Plate

Divide dressed arugula between two plates (or arrange on a single platter). Arrange seasoned heirloom tomato wedges around and atop the arugula. Place 1 burrata ball on each plate in the center of the tomatoes and arugula.

Finish

Drizzle remaining 1 tablespoon extra-virgin olive oil over tomatoes and burrata. Spoon balsamic glaze in a thin ribbon across the plate and over the burrata (about 1–2 tablespoons glaze per serving). Tear basil leaves and scatter over the salad. Sprinkle remaining 1/2 teaspoon sea salt, remaining 1/2 teaspoon black pepper, and optional toasted pine nuts and flaky sea salt if using.

To eat, pierce the burrata so the creamy interior spills over the tomatoes and arugula. Serve immediately.