Shrimp and Grits

INGREDIENTS

• 1/2 shelled fresh fava beans (from about 1/2 pound pods) or frozen fava beans, thawed
• Kosher salt
• 1/2 shelled fresh peas (from about 1/2 pound pods) or frozen peas, thawed
• 4 vegetable oil, divided
• 1/4 bacon, coarsely chopped
• 1/4 tasso or andouille sausage, sliced 1/4-inch thick
• 1 1/2 jumbo shrimp, peeled, deveined, shells reserved
• 2 shallots, chopped
• 2 garlic cloves, chopped
• 4 low-sodium chicken broth
• 1 sprig thyme
• 1/2 fresh orange juice
• 1/4 fresh lemon juice
• 1/4 dry white wine
• 2 Worcestershire sauce
• 1 hot pepper sauce (such as Tabasco) plus more
• 1 sugar
• 1 unsalted butter
• Freshly ground black pepper
• 2 kosher salt plus more
• 1 grits (not instant)
• 1/2 mascarpone (about 4 ounces)
• 1/2 (1 stick) unsalted butter, cut into 1-inch pieces