Ingredients

• 2 medium onions, unpeeled, cut into 4 wedges
• 3 celery stalks, cut into 1″ pieces
• 2 large carrots, whole (with tops on) and cut into 1″ pieces 
• 1 head of garlic, halved crosswise
• 6 sprigs flat-leaf parsley
• ½ bunch of thyme
• 3 bay leaves
• 1 Tablespoon whole black peppercorns
• 2 teaspoons kosher salt (optional)

Directions

1. In a stock pot, heat olive over medium high heat. 
2. Add onions and cook until golden brown, about 3 minutes.
3. Add celery, carrots, and garlic and toss to combine and coat with oil. Reduce heat to medium and cook with lid on, stirring occasionally, until vegetables start to release some liquid and begin to brown, 5–6 minutes. 
4. Stir in parsley, thyme, bay leaves, and peppercorns, then pour in 3 quarts water. Bring to a simmer and let cook for 1 ½ -2 hours. 
5. Strain stock through a fine-mesh sieve into a large bowl; discard solids. Add salt (if using), stirring to dissolve. Let cool.