In a small mixing bowl, whisk the olive oil, vinegar, garlic, and herbs until incorporated. Season the vinaigrette with salt and pepper. With a serrated knife, quarter the Heirloom tomatoes. Slice the Creole tomato into 1/2-inch slices. Cut the Vidalia onion into thin slices or rings. Peel and remove the pit of the avocados. Slice the avocados into 1-inch slices. Season all the vegetables (both sides) with salt and fresh black pepper. Arrange all the vegetables on a large platter along with the cheese. Drizzle the dressing over the entire platter. Serve the salad with the croutons.