Seafood Paella with Brown Rice

Name: Seafood Paella with Brown Rice
Ingredients: 1 kg fish to make the fish stock; 2 liters water; 2 onions; 1 leek; 6 cloves garlic; 2 lemons; 1 sprig fresh parsley; 1 bunch spring garlics or spring onions; 1 teaspoon sweet paprika; 3 mature tomatoes; 1 thick fresh tuna steak, diced; 200 g fresh prawns; a few strands of saffron; 2 tomatoes