Place parchment paper on a sheet pan and place the fillets on top. Spread the baby tomatoes, garlic and spinach leaves on top of the fillets, drizzle with olive oil, season and cover with a second piece of parchment paper.
Seal the parchment paper like an envelope and oven bake at 180°C for 20 minutes.
When they are ready, open the paper envelope carefully and place the fillets on the plates.
Optionally, drizzle the balsamic glaze over the fillets and sprinkle with the flaked almonds.