Preheat oven to 200°C / 392°F (or 180°C / 356°F if using convection). Finely chop the capers. In a bowl, mix the capers, parsley, thyme, basil, mustard, chopped almonds, and breadcrumbs.
Add olive oil until the mixture forms a compact, moist mass that holds together. Season generously with salt and pepper.
Rinse the cod fillets and pat them dry with paper towels. Season each fillet on both sides with salt and pepper. Place them in a greased casserole dish. Spread the herb mixture evenly over each fillet. Bake for 15-20 minutes until the fish is cooked through and flakes easily with a fork.
While the fish bakes, dice the tomatoes. Peel and mince the onion and garlic. Heat 2 tablespoons of olive oil in a pan over medium heat. Add the onion and garlic, cook for 1-2 minutes until they begin to soften. Add the diced tomatoes and simmer for 2 minutes. Season the sauce with honey, balsamic vinegar, salt, and pepper to taste. Serve the tomato sauce alongside the baked cod.