Brown sausage (5 min): Heat a large skillet over medium-high. Add butter, then the sausage. Fry until lightly browned.
Soften onion (3–4 min): Add onion; cook, stirring, until translucent.
Build the base (1–2 min): Stir in tomato paste, paprika, and (if using) soy/Worcestershire; cook 60–90 seconds.
Simmer (6–8 min): Pour in stock, scrape the pan, and simmer until slightly reduced.
Finish the sauce (5–6 min): Lower heat to medium. Stir in cream and Dijon; simmer gently until glossy and lightly thickened. Season with salt and pepper.