Heat a large cast-iron pan over medium-high heat or place over campfire coals. Add olive oil and roast red onion, carrots, turnips, beets, and red pepper flakes. Add peppers and green beans and cook until warmed through. Stir in garlic and cherry tomatoes and cook until garlic is roasted. Deglaze pan with lemon juice, then fold in butter and herbs. Stir to coat vegetables with butter as it melts. Season to taste with salt and pepper, then garnish with crispy ham and marigold flowers.