Pete Evans on grilling outside: "It's just more fun than cooking indoors—and it gets my kids off Facebook." More Amazing Steaks
In a medium saucepan, combine the vinegar, dry mustard and cloves and simmer over moderate heat until reduced by half, about 10 minutes. Transfer the vinegar to a heatproof bowl. Wipe out the saucepan.
Add the 2 tablespoons of oil to the saucepan, along with the onion, garlic and cumin. Cook over moderately low heat until the onion is softened and fragrant, about 5 minutes. Add the brown sugar and tomatoes and cook until softened, about 5 minutes. Add the reduced vinegar and the barbecue sauce and simmer until reduced to 2 cups, about 5 minutes. Transfer the sauce to a blender and puree until smooth. Add the sambal oelek and season with salt and pepper.
Light a grill or preheat a grill pan. Rub the steaks with oil and season generously with salt and pepper. Grill over moderately high heat, turning once, until the steaks are lightly charred and medium-rare, about 6 minutes total. Let the steaks rest for 5 minutes, then garnish with rosemary and serve with the barbecue sauce.
Barons Black Wattle Original Ale, laced with native Australian wattle seeds, is rich, creamy and big enough for these substantial steaks. A bold Shiraz would also be delicious.