To make the tri-tip, in a bowl, whisk together the tomato juice, wine, salt, pepper, lemon juice, Worcestershire sauce, garlic, garlic powder, horseradish and olive oil until well combined. Transfer to a 1-gallon sealable plastic bag and add the tri-tip. Seal the bag and refrigerate for at least 8 hours or up to 24 hours.

Preheat a gas grill on high, or prepare a charcoal fire and let the coals become hot and grey in color. 

Remove the tri-tip from the marinade and place in the center of the grill. Cook, turning once, until the outside is brown in color (try not to burn the meat). Move the tri-tip over medium heat and cook until an instant-read thermometer inserted into the center of the meat registers 120° to 130°F for medium-rare to medium. 

Transfer the tri-tip to a carving board, cover loosely with aluminum foil and let rest for 5 to 10 minutes. Cut the tri-tip into thin strips and place on baguette slices. Top each with a spoonful of chimichurri sauce (recipe below). 

To make the chimichurri sauce, in a food processor or blender fitted with the blade attachment, combine the garlic, parsley, oregano, vinegar, red pepper flakes, salt and black pepper. Process until the ingredients are finely chopped, stopping and scraping down the sides of the bowl with a rubber spatula as needed, about 1 minute total. 

With the motor running, add the olive oil in a slow, steady stream until blended. The sauce can be made up to 1 day in advance; cover and refrigerate.