Creamy Tomato Orzo Risotto with Shrimp

Ingredients

• 4 tbsp unsalted butter (divided)
• 3/4 cup diced white onion
• 5 garlic cloves crushed
• 3 tbsp tomato paste
• 2 cups orzo
• 6 to 7 cups warm unsalted chicken stock
• 1 1/2 lbs shrimp
• 1 1/2 tsp kosher salt (divided)
• 1/2 tsp dried oregano
• 1/4 teaspoon black pepper
• 1/4 tsp red pepper flakes
• 1/3 cup whipping cream
• 1/2 cup grated parm
• 1 teaspoon red wine vinegar
• fresh basil (for topping)