Rinse clams under cold running water, scrubbing shells with a brush to remove any grit. Discard any clams with cracked shells or ones that don't close when tapped.

Place a large skillet or Dutch oven over medium-high heat. Add butter and let it melt completely, swirling to coat the bottom. The butter should foam slightly but not brown.

Add minced garlic to the melted butter and sauté for 30-60 seconds until fragrant. Don't let the garlic brown or it will taste bitter. Add red pepper flakes now if using.

Pour in white wine, which will bubble and steam immediately. Add the clean clams to the pan in a single layer if possible. Cover the pan with a tight-fitting lid.

Cook covered for 5-8 minutes, shaking the pan occasionally. Once most clams have opened wide, they're ready. Discard any stubborn clams that remain closed after cooking.

Remove from heat and stir in fresh lemon juice and chopped parsley. Taste the broth and season with salt and pepper as needed. Serve immediately with warm crusty bread.