Shell fresh beans if using. Cook beans in boiling salted water until tender. Drain and rinse under cold water. Set aside.
Cook bacon until crisp, drain and crumble. Cook onion in bacon fat and oil until softened. Add garlic, tomatoes, corn, and vinegar. Cook until tomatoes begin to soften.
Remove from heat and gently stir in cooked beans and half of bacon. Cool succotash to room temperature and gently stir in basil and arugula. Season with salt, pepper, and additional sherry vinegar. Toss with croutons.
For garlic croutons: Cut slices of bread, brush with oil, and grill until golden brown. Rub with garlic, sprinkle with salt, cut into cubes, and toss into succotash.
