Thoroughly rinse produce and pat dry. Preheat oven to 425 degrees and line a baking sheet with foil. Peel rutabaga and cut into ½" dice. Halve Brussels sprouts. Peel, halve, and cut red onion into ½" slices. Peel carrot and slice into 1" pieces. Trim and peel watermelon radish. Slice as thinly as possible, stack, and cut into matchsticks. Coarsely chop garlic. Stem thyme.

Toss rutabaga, Brussels sprouts, red onion, carrot, half of garlic, and half of thyme on baking sheet with 1 Tbsp. olive oil. Season with a pinch of salt and pepper and roast for 20 minutes, or until vegetables are caramelized and tender. Allow to cool slightly.

While vegetables are roasting, combine red wine vinegar, remaining garlic, remaining thyme, 1 tsp. water and 3 Tbsp. olive oil in a mixing bowl. Season with a pinch of salt and pepper, add croutons, and toss. The longer the croutons can sit and absorb the dressing, the better they will be!

Add the roasted vegetables and arugula to bowl with croutons. Toss gently to combine.

Divide panzanella between two plates or wide bowls. Garnish with watermelon radish and shaved parmesan.