Charred Broccoli Salad With Figs

Name: Charred Broccoli Salad With Figs
Ingredients: 2 lb. broccoli (about 3 medium heads), ends trimmed, stems peeled; ¼ cup extra-virgin olive oil; Kosher salt, freshly ground pepper; ½ cup labneh or whole-milk plain Greek yogurt; 2 small garlic cloves, finely grated, divided; ½ cup coarsely chopped dried figs (such as Turkish or Mission); Zest of ½ lemon; 3 Tbsp. fresh lemon juice, divided; 1 cup tahini; Small handful of mixed tender herbs (such as mint, tarragon, and/or parsley), leaves torn if large; Sumac (for serving)