Place water and broth in a large saucepan or medium pot (big enough to hold sausages in a single layer). Add bay leaves, peppercorns, smashed garlic cloves, thyme, and salt. Add the quartered onion and whole cloves (if using) to the pot.

Bring the liquid to a gentle simmer over medium-high heat. Do not let it come to a rolling boil; maintain a gentle simmer to keep the sausages tender and to prevent splitting.

Add the sausages to the simmering liquid. Reduce heat to low or medium-low so the liquid stays just below boiling. Simmer the sausages for 8–12 minutes for fresh sausages or 6–8 minutes for fully cooked smoked sausages until heated through (internal temperature for fresh sausages should reach 160°F / 71°C for pork or 165°F / 74°C for poultry).

Occasionally spoon some hot liquid over the sausages to ensure even heating. Use a meat thermometer to confirm doneness.

Aromatics & Finish

When sausages are cooked through, remove them with tongs to a plate and loosely cover with foil to rest 3–5 minutes.

Increase heat under the cooking liquid and reduce for 3–4 minutes until slightly concentrated (optional). Stir in the vinegar to brighten the flavor and the butter to add a light glaze; simmer 30 seconds more.

Slice one sausage open to check color and juices if unsure; the juices should run clear and any pink should be gone for fresh pork (or at safe internal temperature).

Transfer the reduced cooking liquid and aromatics to a small bowl or spoon some over sausages before serving. Sprinkle chopped parsley over the sausages for color and freshness.

To Serve

Warm buns or bread briefly in an oven at 350°F (175°C) for 5 minutes or toast in a skillet until lightly browned.

Place each sausage in a bun or on bread. Add mustard and pickle chips as desired. Spoon a little of the reserved aromatic cooking liquid over the sausage for extra moisture and flavor.

Serve immediately while hot with remaining mustard on the side.