Vegetables à la Barigoule with Vanilla Recipe

Ingredients

• 1 lemon
• 2 small heads of broccoli, cut into 2" florets
• Kosher salt
• 4 carrots, peeled, halved lengthwise
• 2 medium white onions, each cut into 6 wedges with some root attached
• 1 12-ounce bunch asparagus, trimmed
• 1 fennel bulb, trimmed, cut into 8 wedges with some core attached
• 2 cups low-salt chicken broth
• 1 vanilla bean, split lengthwise
• 3 tablespoons olive oil, divided
• 4 garlic cloves, crushed
• 10 coriander seeds
• 5 whole black peppercorns
• 4 sprigs thyme
• 1 bay leaf
• 1 teaspoon (or more) Sherry vinegar
• Freshly ground black pepper
• Fresh cilantro leaves