The thing I like most about a recipe like this is that you have a chance to showcase your favorite type of cheese in a way that's hard for people to resist. I like goat cheese for the "tang" factor and the supple texture. This goes great with a bowl of my chicken soup but can really fit in with any soup for the "comfort" factor.
Heat a large skillet, over medium heat, and add the olive oil. When the oil begins to smoke lightly, shut off the heat and add the thyme leaves. The thyme should make a crackling sound as it hits the oil, cooking it slightly and mellowing the flavor. Add the bread in a single layer. Turn the heat back on and cook over medium heat until the first side browns, 2 to 3 minutes.
Use a pair of tongs to turn the toasts on their second side and season with kosher salt. Top each round with a slice of cheese and continue cooking them over very low heat or off the heat, for 2 to 3 minutes. Adjust the seasonings with sea salt, to taste. Serve alongside soup, if desired.