This is a beautiful, fresh, and healthy dish that looks like you put more effort into it than you actually did. You can even call it tilapia “en papillote” if you want to sound all French and fancy.
Heat olive oil in a small skillet and cook garlic and red pepper flakes until fragrant, about 2 minutes. Turn the heat off and stir in the tomatoes and olives. Season with salt and pepper.
Cut two large pieces of parchment paper (each about 16 inches in length). When you lay a tilapia filet in the middle of the paper, you want enough slack to overlap the fish on top and extend at least 3 inches beyond the fish at each end.
Place a filet in the middle of one piece of parchment paper. Like you're wrapping a birthday present, pull the long sides up over the fish to meet in the middle, then twist one end of the parchment like a tootsie roll wrapper and tuck underneath the fish, leaving one end still open. Repeat with the second filet.
With one hand, lift up the open end of one parchment envelope so that nothing can spill out. With your other hand, spoon half the contents of the skillet (the garlic, red pepper, tomatoes, and olives) on top of the fish.
Being careful not to spill, add two tablespoons white wine, then top with 1 tablespoon butter, 1 lemon slice, and 3 thyme sprigs.
To seal the packet, fold the parchment over the top of the fish lengthwise, then twist the remaining open end of parchment like the other end and fold under the fish. Creating the parchment packet is a really hard process to describe in writing, but basically you are trying to create a tight envelope that will seal in the liquids and steam as the fish cooks. It doesn't have to look pretty (and won't, if it looks anything like mine).
Place the packets on a baking sheet and bake for about 11-12 minutes, or until the fish is flaky and white throughout. Be careful opening as steam will release.
Serve in the parchment or remove the fish and packet contents to a plate.