Speedy Shrimp and Grits

Name: Speedy Shrimp and Grits
Ingredients: 5 cups low-sodium chicken stock; 3/4 cup quick grits; 1 1/2 cups grated pepper jack cheese; 1 1/2 cups grated sharp Cheddar; 1/2 cup mascarpone; 4 tablespoons butter; 1 tablespoon olive oil; 1 1/2 pounds peeled and cleaned jumbo shrimp; 1 tablespoon Cajun seasoning; Kosher salt and freshly ground black pepper; 6 strips bacon, chopped; 1 onion, chopped; 1 red bell pepper, chopped; 1 jalapeno pepper, chopped; 1 tablespoon tomato paste; Hot sauce, as needed; Juice of 1/2 lemon; 3 scallions, chopped, for garnish