Halibut Baked With Herbs

• 6 portions halibut steaks
• 1/2 instant potato flakes
• 425 gr fillet
• 60 gr rice chex
• 45 ml lemon juice
• 45 gr butter
• 28 gr parmesan cheese (grated)
• 5 ml dry mustard
• 3 gr paprika
• 2 gr onion flakes rehydrated