Combine sachet of Seasoning-Spice Blend (contained within the KNORR Tuna Mate Chedda-Melt box), milk and water in a large saucepan.
Stir in mustard and Worcestershire sauce.
Add fish fillets and peas, and stir in the uncooked pasta (contained within the KNORR Tuna Mate Chedda-Melt box).
Bring to the boil, stirring occasionally and simmer for 15-20 min, stirring gently to avoid the fish breaking up, until the pasta is cooked.
Stir in the mascarpone cheese and dill.
Season with salt and pepper and serve.