In a large Dutch oven, melt ½ cup butter and then sauté the onions, carrots and celery over medium heat – allowing them to soften a little – about 5 minutes. Add the potato and add only enough chicken broth to barely cover (about 3 cups). Stir to combine and then cook until the potato is just barely tender (8-10 minutes).
As the potato is cooking, melt the remaining ¼ cup of butter in a skillet over medium heat and then add the lobster pieces to the skillet. Cook the lobster until the butter has taken on an orangey-red colour from the lobster, and the lobster has heated through. About 5 minutes. Remove from heat and set aside.
Add the basil, oregano, celery salt, paprika, pepper and Tabasco sauce to the vegetables in the Dutch oven and stir to combine. It will seem like a lot of spices, don’t worry. Layer the haddock, cod and scallops on top. Gently press the fish down so it is just covered with liquid. Cook only until fish barely flakes (4-5 minutes).
Add the lobster and every last drop of butter from the skillet to the Dutch oven. Reduce the heat to low. Add the heavy cream and the light cream. If you think you’re going to run out of room in the pot, skimp on the light cream, not the heavy.
Allow the chowder to warm through. Keep on low heat until serving or refrigerate and slowly heat up before serving. Don’t allow to boil.