For the concasse, plunge 3 plum tomatoes in boiling water for 15 seconds, remove to cold water to stop cooking process, now peel them , cut around equator , remove seeds , and chop.
In a large sauté pan heat olive oil, add mushrooms cook 4 minutes. Remove from pan + reserve. Add butter to pan , then garlic and shallots cooking gently 3 or 4 minutes. Dust shrimp and scollops with flour and add to pan . Cook on each side but only until half done , something like a minute on each side. At this point add the rest of your ingredients including mushrooms , bringing everything to a boil , stirring, flipping and basting your shrimp and scollops .Cooking only an additional 2 or 3 more minutes . Yum