For the red pepper tapenade: In a food processor, add the red peppers, olives, raisins, olive oil, parsley, capers and brine, vinegar, red pepper flakes, garlic confit and lemon juice and process until combined but still slightly chunky. Season with salt and pepper. Set aside.
For the tortilla: Preheat the oven to 300 degrees F.
In a 12-inch ovenproof nonstick pan, heat the olive oil over medium heat until hot. Add the potatoes and onions, season with salt and pepper and cook, stirring frequently, until the potatoes are tender but not breaking, 8 to 10 minutes. Strain the oil from the potato mixture and reserve 1 tablespoon of the oil. Leave the potato mixture in the pan.
In a small nonstick pan, toast the panko breadcrumbs in the reserved 1 tablespoon oil. Season with salt and pepper.
In a large bowl, whisk the eggs to a smooth, even consistency. Add the Gruyere, cherry peppers, chopped parsley, tomato, toasted breadcrumbs and 1/4 cup of the Parmesan. Season with salt and pepper and stir to combine. Pour the egg mixture into the pan with the potato mixture. Cook over medium-low heat until the eggs are just starting to set, 5 to 6 minutes. Transfer to the oven and bake until the eggs are set, 20 to 30 minutes. Let cool until warm.
Slide the tortilla onto a cutting board or turnout onto a large serving plate and cut into slices. Serve the slices at room temperature topped with the red pepper tapenade, a drizzle of extra-virgin olive oil and a sprinkle of the remaining Parmesan.
Put the garlic cloves in a small pot and cover with the olive oil. Cook over low heat until the cloves are very soft, 50 minutes to 1 hour. Let cool, then store in a resealable container in the refrigerator.