Preheat the griddled cast iron pan in the oven to 425° F.
Place the tomatoes in a 9X12 baking dish and season with salt and pepper. Toss with 1 tbsp olive oil and 1 tbsp balsamic. Roast the tomatoes for 20-25 minutes, until they start to burst. When finished, remove from the oven and garnish with fresh basil.
Slice the eggplant into 1 inch thick rounds. Lay the eggplant rounds flat on a cutting board and sprinkle salt over top to draw out some of the moisture. After about 5 minutes, pat the eggplant dry with a paper towel.
1 large eggplant, 1 tablespoon kosher salt
Brush a thin layer of olive oil over one side of the eggplant and season with Montreal seasoning, paprika, garlic powder, and sugar.
1 tablespoon Montreal seasoning, 1 teaspoon paprika, 1 teaspoon garlic powder, 1 teaspoon light brown sugar
Carefully remove the griddled pan and arrange the eggplant in a single layer in the pan. If you have sliced eggplant that doesn't fit in the pan, feel free to put the extras on a lightly greased baking sheet or another griddled pan. Bake the eggplant alongside the tomatoes for 20-25 minutes.
Meanwhile, heat a large non-stick skillet on medium heat with 1 tbsp olive oil and 1 tbsp butter. Add the onions, toss to coat, and cook, stirring occasionally for 15-20 minutes, until the onions have started to caramelize.
1 tablespoon unsalted butter, 2 medium-large white onions,
Transfer the eggplant to a serving dish and top with the roasted tomatoes and caramelized onions. Garnish with more fresh basil if desired.
2 tablespoons fresh basil,
Notes
Try drizzling a balsamic glaze over top for more flavor!