Instant Pot Mac & Cheese with Lemony Garlic Breadcrumbs

For the mac and cheese:

• 2 tablespoons unsalted butter divided
• 2 1/2 cups milk whole
• 1/4 cup heavy cream
• 6 ounces cream cheese at room temperature
• 1 garlic clove
• 1 teaspoon dried mustard
• 1 tsp kosher salt
• 1/4 teaspoon black pepper freshly ground
• 1/8 teaspoon cayenne pepper
• Pinch nutmeg freshly grated
• 12 ounces dried pasta
• 8 ounces cheddar cheese sharp, grated

For the breadcrumbs:

• 3 tablespoons butter
• 2 garlic cloves, finely chopped
• 4 ounces breadcrumb about 2 1/2 cups, fresh
• kosher salt
• black pepper freshly ground
• lemon zest of 1/2

Chopped parsley, for serving