Heat 2 tablespoons of olive oil in a medium skillet over medium heat. Add minced garlic and diced jalapeño, sautéing for 3-4 minutes until golden and fragrant. Transfer to a blender with roasted red peppers, sun-dried tomatoes, nuts, vinegar, paprika, parsley, and salt. Blend until smooth.

In a large mixing bowl, mash the drained chickpeas lightly with a fork. Stir in bell pepper, onion, chopped sun-dried tomatoes, and optional diced jalapeño. Mix in half of the prepared romesco sauce until desired consistency is reached.

Preheat oven to 425°F. Cut cabbage into wedges, drizzle with olive oil, and sprinkle with salt. Roast for 15 minutes until tender and caramelized, then cool slightly.

Spread cream cheese on both slices of bread. Layer chickpea salad on one slice, top with roasted cabbage wedges and marinated onions if desired. Close the sandwich and serve.