Prepare all ingredients by chopping parsley and mincing garlic. Measure out butter, half-and-half cream, and grated Parmesan cheese.

Melt the unsalted butter in a medium saucepan over medium heat for about 2 minutes, ensuring it doesn’t brown.

Add minced garlic and sauté for 1-2 minutes until fragrant but not browned.

Whisk in all-purpose flour and cook for about 1 minute until light golden.

Gradually pour in half-and-half cream while whisking continuously for 2-3 minutes until smooth.

Stir in grated Parmesan cheese and mix until melted, about 3-4 minutes.

Add lemon zest, fresh parsley, and crushed red pepper flakes. Simmer for another minute.

Remove from heat and serve warm as a dip for pizza or breadsticks.