Preheat oven to 450 degrees F. Spread grapes onto a non-stick sheet pan. Drizzle with olive oil and sprinkle with salt. Lay thyme leaves over top. Toss all together gently with your hands.
Place pan in the oven for 7 minutes or until grapes just begin to burst.
Spread fresh ricotta over bread, topped with the roasted grapes (along with some pan juices.)
Discard thyme sprigs (or strip the sprigs and include the leaves) and enjoy!