Heat a 6-quart pressure cooker over medium-high heat. Add butter to cooker; swirl until butter melts. Add shallots; sauté 2 minutes. Add garlic; sauté for 30 seconds, stirring constantly. Add rice; cook 1 minute, stirring constantly. Add 1/2 cup prosecco; cook 1 minute or until liquid is absorbed, stirring constantly. Stir in remaining 1/2 cup prosecco and broth. Close lid securely; bring to high pressure over high heat. Adjust heat to medium or level needed to maintain high pressure; cook 8 minutes. Remove from heat; release pressure through steam vent, or place cooker under cold running water to release pressure. Remove lid. Grate 1 3/4 ounces cheese; stir in grated cheese and remaining ingredients. Let stand 4 minutes to thicken. Shave remaining 1/4 ounce cheese, and top with shavings.