Mix kosher salt, black pepper, garlic powder, paprika, onion powder, and dried oregano into a single rub with an even color and no dry clumps (visual cue: uniform speckled mixture).

Pat the tri-tip roast dry, then rub it all over with olive oil so the surface looks glossy and tacky (visual cue: oil sheen across the roast).

Coat the tri-tip generously with the spice rub, pressing lightly so it adheres in an even layer (visual cue: thick, reddish-brown crust covering the meat).

Let the seasoned tri-tip sit at room temperature for 30 minutes so it warms slightly and begins seasoning the surface (visual cue: rub looks slightly absorbed and the meat looks less wet).

Sear the tri-tip over high heat for 5 minutes per side so a dark crust forms quickly (visual cue: browned exterior and crisp-looking edges).

Move to indirect heat and cook until the center reads 130-135°F for medium-rare (visual cue: thermometer inserted in the thickest part shows 130-135°F and juices look clear).

Sear the tri-tip in a hot skillet to build color on the exterior (visual cue: vigorous browning and a deep crust on all sides).

Roast at 425°F for 20-25 minutes, checking until the center reaches 130-135°F for medium-rare (visual cue: thermometer reads 130-135°F and the crust stays intact).

Rest the tri-tip for 15 minutes before slicing so juices redistribute (visual cue: meat surface looks set, not actively pooling).

Slice against the grain right before serving for tender slices, showing the pink medium-rare interior (visual cue: visible pink center with crusty outer edges).