Kolsch-Braied Pork Belly

Ingredients

• 2 Tbsp kosher salt
• 2 Tbsp dry mustard powder
• 2 Tbsp mustard seeds
• 1 Tbsp sugar
• 1 lemon, zested
• 2 sprigs rosemary, picked and finely chopped
• 2 garlic cloves, smashed and finely chopped
• Pinch crushed red pepper flakes
• 3 pounds fresh pork belly, skin removed
• Extra-virgin olive oil
• 1 onion, julienned
• 2 ribs celery, sliced on the bias
• 1/2 fennel bulb, tough middle discarded and remaining bulb julienned
• Kosher salt
• 2 cups Kolsch
• 1/4 cup whole-grain mustard
• 2 to 3 cups chicken stock
• Thyme bundle
• 3 to 4 bay leaves