Preheat the oven to 350 degrees F. Line a baking sheet with aluminum foil.

Place the cubed sweet rolls in a bowl and toss with a small amount of olive oil. Place the rolls on the prepared baking sheet and sprinkle with salt. Toast in the oven, checking every 5 minutes and flipping when the bottoms turn golden so that they crisp evenly. This should take around 15 minutes total. Set aside.

Preheat a grill until very hot. Brush a light coating of high heat oil or clarified butter on the zucchini. Place the zucchini slices on the grill and cook for 2 minutes, uncovered, then flip and cook the other sides for an additional 2 minutes.

Place the 2 tablespoons olive oil, lemon juice, and a pinch of salt and pepper into a jar with a tight fitting lid. Shake vigorously to emulsify the ingredients.

Place a large handful of baby arugula on 2 salad plates. Top each salad with 2 slices of zucchini, 2 tablespoons of feta and some of the croutons (there may be leftover croutons; save for later use).

Drizzle lightly with vinaigrette.