Roast the garlic (optional): Cut the top off the garlic head, drizzle with olive oil, wrap in foil, and roast at 325°F for 1 hour until soft. Squeeze out about 2 tsp of roasted garlic.

Build the base: In a medium saucepan, combine the water, pineapple juice, teriyaki, soy sauce, and brown sugar. Bring to a boil over medium heat, stirring until the sugar dissolves.

Add the rest: Reduce to a simmer and stir in the roasted garlic, minced onion, lemon juice, Jack Daniel's, crushed pineapple, and cayenne.

Reduce: Simmer gently for 35–45 minutes, stirring occasionally, until the sauce reduces by about half and turns thick and syrupy. Watch closely near the end so it doesn't boil over.

Cool and store: Remove from heat and let cool — it thickens as it sits. Transfer to a jar and refrigerate.