Preheat the oven to 350 degrees F.
Cut 4 pieces of parchment paper into 1-foot squares and place on a flat surface (may use aluminum foil if desired.) In the center each piece, lay down a piece of catfish. Divide the remaining ingredients among the servings. Fold in the edges of the parchment paper and seal tightly to form a bundle. Rub the top of the parchment with a little olive oil to prevent the paper from scorching in the oven. Place packages on baking sheet and bake until the packages puff and fish is opaque, about 15 minutes. The potatoes and tomatoes should be very soft.
Transfer packages to plates. Allow each guest to open his or her own package at the table. Serve with lemon wedges.
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