Steak: Mix the wine, cassis, oil and black pepper in a nonreactive dish. Add the steak, turn to coat, and marinate at room temperature 1 hour.;
Sauce: Pulse the herbs and garlic in a food processor until coarsely chopped. Add 3/4 cup oil, 1/4 cup vinegar and salt and pepper, to taste, and pulse to make a soupy vinaigrette ¿ it will look a bit creamy until it settles. Add more oil and/or vinegar if too thick. Set aside.
Preheat the grill to high. Remove the steak from the marinade and season with salt and more pepper. Grill, covered, until nicely charred and medium rare, 3 to 4 minutes per side. Remove from the grill and rest 5 to 10 minutes before slicing across the grain.
Relish: Brush the onions with some canola oil and season with rub, salt and pepper. Grill the onions, turning, until charred and soft. Remove from the grill and chop coarsely. Chop again with the green onions and then stir them together with the chile, oil, vinegar, and salt and pepper.
Slice the baguette on a diagonal 1/4-inch thick. Brush with oil, season with salt and pepper and grill briefly, until just starting to crisp. Top each piece with some sauce, a slice or 2 of steak, more sauce and some relish.