Wash red potatoes and cut larger ones in half. Place in a large pot and cover with cold water by 1 inch.

Bring to a boil, add 1 tablespoon salt, then reduce to medium heat. Simmer gently for 10–15 minutes until fork-tender.

Drain and return to the hot pot to steam-dry for a few minutes. Cut into 3/4-inch chunks once cool enough to handle.

In a large skillet, cook turkey bacon over medium heat until chewy and crisp. Remove with a slotted spoon and set aside.

Add diced onion to the skillet with turkey bacon grease. Cook over medium heat for 4 minutes, stirring often.

Stir in minced garlic and cook for 1 minute. Remove skillet from heat.

Stir in both mustards, sugar, remaining salt, and pepper. Slowly add apple cider vinegar, stirring constantly.

Return skillet to medium heat, bring mixture to a simmer, and cook for 2–3 minutes, stirring occasionally.

Remove from heat, add potatoes, and fold gently to coat. Add turkey bacon and parsley, then fold again.

Season with additional pepper if desired. Serve warm, at room temperature, or chilled.