Step 1

Bring vinegar, wine, sugar, and salt to a simmer over medium-high heat in a small saucepan. Place jalapeños in a small bowl or jar and pour brine over. Let sit until cool, or at least 1 hour.

Step 2

Do Ahead: Pickled jalapeños can be made 1 week ahead. Cover and chill.

Step 3

Prepare a grill for medium, direct heat. Purée one avocado half, garlic, tahini, lemon zest, 5 Tbsp. lemon juice, ⅓ cup cilantro, 4 Tbsp. oil, and 2 Tbsp. water in a blender, adding a splash of water if needed, until smooth. Season with salt and pepper.

Step 4

Toss broccoli and onion with 2 Tbsp. oil; season with salt and pepper. Grill, turning occasionally, until broccoli crowns are dark brown in places and stems are crisp-tender, 5–7 minutes. Let cool slightly.

Step 5

Coarsely chop broccoli and onion. Toss in a medium bowl with remaining 2 Tbsp. lemon juice and 2 Tbsp. oil; season with salt and pepper.

Step 6

Spread tahini dressing on a serving platter and top with broccoli mixture. Drain some of the pickled jalapeños (you will have extra). Top broccoli mixture with remaining chopped half of avocado, sesame seeds, drained jalapeños, and more cilantro.