How to Make It
Light a grill. Using the flat side of a chef's knife, mash the garlic with a large pinch of salt. Transfer the paste to a bowl and whisk in the cream, mayonnaise, vinegar and mustard. Whisk in the 1/4 cup plus 2 tablespoons of olive oil in a thin stream until emulsified. Add the parsley and oregano and season with salt and pepper.
Brush the steak with olive oil and season generously with salt and pepper. Grill the steak over a medium-high fire, turning occasionally, about 10 minutes for medium-rare meat. Transfer the steak to a cutting board and let rest for 10 minutes, then slice thinly. Meanwhile, brush the baguette slices with olive oil and grill until toasted, 2 to 3 minutes. Cut them into cubes.
In a large bowl, combine the escarole with the endives, radishes, avocado and bread cubes. Add the dressing and toss to coat. Transfer the salad to a large platter or plates, top with the steak and serve.