1. Cut each calamari tube into 1⁄4-inch strips lengthwise. If using the tentacles, cut into segments.
2. Coat a large saute pan generously with olive oil. Add the smashed garlic cloves and red pepper and bring to high heat. When the garlic is golden brown and very aromatic, 2 to 3 minutes, remove it from the pan and ditch it-it has fulfilled its garlic destiny!
3. Add the potatoes to the garlic-infused oil and bring to medium-high heat; cook until brown on one side, about 5 minutes, then turn and brown the second side. Remove the potatoes from the pan and reserve.
4. Add the calamari to the pan and toss it in the hot oil. Season with salt and cook for 1 to 2 minutes, or until it turns opaque. Add the wine and the olives and continue to cook until the wine has reduced by about half, 3 to 5 minutes. Taste and adjust the seasoning if needed.
5. While the calamari is cooking, toast or grill the bread until charred on both sides, 3 to 4 minutes total. Rub the bread with the remaining garlic clove and drizzle generously with olive oil.
Divide the arugula between four serving bowls. Spoon the reserved potatoes, calamari, and the pan juices over the greens. Cut each piece of bread in half on the bias and lay it on top of the calamari; garnish with chives and serve.