Preheat the oven to 400 degrees.
Line a rimmed baking sheet with parchment paper. I know my photos show aluminum foil but while that is possible, it is not ideal. There was a little sticking situation.
Place the washed cherry tomatoes in a medium bowl.
Toss the cherry tomatoes with the olive oil and kosher salt.
Add in sliced red onion and halved black olives. Toss everything together.
Place the feta in the middle of the prepared baking sheet. I cut an 8 oz. block of feta in half because it was just for me and my husband.
Add the tomato, red onion, and olive mixture to the pan. I used a slotted spoon because you don't want pools of olive oil in a 400 degree oven.
Sprinkle with fresh thyme and red pepper flakes.
Bake until the cheese is gooey and the tomatoes pop open - about 30 minutes.
While your cheese is baking, prepare your pasta. I used mostaccioli, which is like ziti.
Before draining your pasta, scoop out about 1/2 cup of the pasta water with a ladle and set it aside.
Place your drained pasta in a serving dish.
Place the melted cheese and veggies on the pasta and mix everything together. If you feel that you need to stretch out the sauce a bit, add a little bit of pasta water until you reach the desired consistency.