Slicing this sturdy cut of beef very thinly after grilling makes it more tender. What to drink: Spicy, jammy Zinfandel from California pairs beautifully with barbecue — as does pale ale.
Prepare barbecue (medium heat). Mix garlic powder, 1 teaspoon salt, and 1/2 teaspoon pepper in small bowl. Brush both sides of tri-tips with oil and sprinkle with garlic-powder mixture, pressing to adhere. Grill tri-tips 5 minutes per side. Reduce heat to medium-low, or if using charcoal grill, move meat to cooler side of grill. Cover and grill until thermometer inserted into thickest part of meat registers 125°F to 130°F for medium-rare, brushing with barbecue sauce and turning every 10 minutes, about 30 minutes longer.
03Transfer tri-tips to work surface; let stand 10 minutes. Cut meat crosswise into very thin slices; arrange on platter. Surround with caramelized onions and serve.