Place an oven rack in the center of the oven; preheat to 450°F. Wash and dry the fresh produce. Cut out and discard the core of the cabbage; thinly slice the leaves. Cut off and discard the stem of the peppers; remove the cores. Thinly slice lengthwise. In a large bowl, combine the buttermilk, vinegar, half the mayonnaise, and ranch dressing. Season with salt and pepper. Add the sliced cabbage and sliced peppers; stir to thoroughly coat. Set aside to marinate, stirring occasionally, at least 10 minutes. Taste, then season with salt and pepper if desired. Pick the thyme leaves off the stems. Halve the baguettes lengthwise. In a bowl, combine the cheese, caramelized onions, mustard, remaining mayonnaise, worcestershire sauce, and half the thyme leaves.

In a small pot, combine the broth and remaining thyme leaves. Cook on medium-high, 3 to 4 minutes, or until slightly reduced. Turn off the heat; taste, then season with salt and pepper if desired.

Meanwhile, in a bowl, combine the beef and spice blend. Season with salt and pepper; gently mix to combine. Form the mixture into four 1/4-inch-thick patties.

In a medium pan (nonstick, if you have one), heat a drizzle of olive oil on medium-high until hot. Add the patties. Cook 2 to 4 minutes per side, or until browned and cooked through.* Transfer to a work surface. 

*The USDA recommends a minimum safe cooking temperature of 160°F for beef.

Meanwhile, line a sheet pan with foil. Transfer the halved baguettes to the foil, cut side up. Evenly spread the cheese mixture onto the cut sides of the baguettes. Toast in the oven 4 to 6 minutes, or until the cheese is melted and the bread is toasted.

Reheat the dip on medium-high, stirring constantly, 30 seconds to 1 minute, or until heated through. Turn off the heat. Assemble the sandwiches using the toasted baguettes and cooked patties. Halve crosswise. Serve the sandwiches with the slaw and dip on the side. Enjoy!