Richard and Suzanne's Louisiana Crawfish Pasta

INGREDIENTS

• 1 (16 ounce) package bow tie pasta
• 3/4 stick butter
• 1 clove garlic, minced
• salt and pepper to taste
• 1 yellow onion, chopped
• 1 tablespoon crushed red pepper flakes, divided
• 1 pound crawfish tails
• 2 pints heavy cream
• 1/2 tablespoon crushed red pepper flakes
• 1 bunch green onions, chopped