Put the almonds in a food processor and process to the consistency of fine bread crumbs. Set aside.
Preheat the oven to 400 F. Cut 4 15-inch squares of parchment (baking) paper. Fold 1 square in half to create a crease, then open up. Place 1 fillet next to the crease. Repeat with the remaining squares and fillets.
Top each fillet with 1/4 of the tomato, onion, almond meal, olive oil, wine, parsley, thyme, saffron, and salt and white pepper. Working with 1 square, fold the paper over the fish and vegetables, then fold the edges several times, crimping to seal the packet completely. Repeat to make 3 more packets. Place the packets on a baking sheet.
Bake until the paper is starting to brown, about 15 minutes. (If the fillets are thin, bake for 12 minutes.) Place the packets on plates. To serve, slit an X in each packet and fold open.