How to Make It
Light a grill. Fill a large bowl with cold water. Holding the escarole by the root end, dip the heads in the water to release any dirt between the leaves. Shake off the excess water.
In a small bowl, whisk 1/2 cup of olive oil with the thyme and garlic. Brush the escarole with garlic oil and season with salt and pepper. Grill over moderate heat until charred outside and tender within, about 20 minutes; brush a few times with garlic oil during grilling. Transfer to a work surface and let cool, then coarsely chop.
Brush the baguette slices with olive oil and season with salt and pepper. Grill until lightly charred on both sides, about 2 minutes.
In a large bowl, toss the escarole with any remaining garlic oil; season with salt and pepper. Top the toasts with the escarole, crème fraîche and trout roe and serve.