Perfect Vegetable Stock

Name: Perfect Vegetable Stock
Ingredients: 2 tsp. whole black peppercorns; 1 tsp. kosher salt; 12 sprigs flat-leaf parsley; 6 sprigs thyme; 4 cloves garlic, crushed; 2 bay leaves; 2 stalks celery, roughly chopped; 2 carrots, halved; 2 bulbs fennel, roughly chopped; 2 leeks, halved; 1 yellow onion, halved