Season the flank steaks on all sides with the Salt Pepper + Chocolate Chiles seasoning. Set aside while you prepare the grill.
Heat a gas or charcoal grill for medium-high direct heat.
While the grill is heating, you can roast the garlic for the mojo de ajo. Combine the garlic cloves and olive oil in a small heat proof skillet. Season with a generous pinch of kosher salt. Set inside the grill and cook with the grill closed for 15 to 20 minutes or until the garlic is tender and lightly golden. Remove from the grill and cool for 10 minutes.
Strain the garlic from the oil into a blender carafe. Add the lime, orange, and grapefruit juice, oregano, a pinch of kosher salt and a few grinds of black pepper. Blend until smooth. Move the mixture to a bowl and then slowly whisk in the garlic oil until the mixture thickens slightly.
Grill the flank steaks over direct heat for 3 to 4 minutes per side. Remove the steaks from the grill and rest, loosely covered with foil for 5 minutes. Add the provolone slices to the still oily skillet – from the garlic – and cook for 4 to 5 minutes while you slice and toast the bread.
Slice the La Brea Bakery Take-and-Bake French Baguette in half lengthwise. Brush the bread with olive oil and grill over direct heat for 30 to 45 seconds, or until charred and crisp. Remove the cheese from the grill.
Thinly slice the flank steak against the grain into very thin slices.
Build the sandwich by piling spring mix onto the bottom piece of bread, layer on the steak slices, pouring on the mojo de ajo sauce. Drizzle more of the mojo sauce onto the top slice of bread. Move the hot cheese to top the steak and top with the top bread pieces. Slice the baguette into 4 to 6 pieces and serve.