PREPARATION: Preheat oven to 150 degrees F and place soup bowls on a rack set at the center to warm while you make the soup.
SWEAT THE VEGETABLES: Heat the olive oil in a 6-quart dutch oven or soup pot over medium flame for two minutes. Add the pinch of crushed red pepper and cook for another minute. Scrape in the chopped onion, leek, garlic, celery, sweet pepper, carrot, and parsley. Stir well and season with ½ teaspoon kosher salt and ¼ teaspoon black pepper along with the thyme and bay leaf. Cover and cook 5-7 minutes until tender, stirring regularly and turning down heat if the vegetables begin to brown.
POUR IN THE WHITE WINE AND TOMATO PASTE and cook uncovered, stirring occasionally, for several minutes or until the wine is mostly absorbed into the vegetables.
POUR IN 5 CUPS OF THE FISH STOCK; add the Tabasco and Parmigiano-Reggiano rind, if using. Cover, raise the heat to high, and bring to a boil. Reduce to a low simmer and cook for 10 minutes or so. Add chickpeas and diced tomato, cooking only until heated through. If the stew has become too thick, add another cup of stock.
WHISK TOGETHER the half and half and cornstarch in a measuring cup. Slowly pour the slurry (the half and half mixture) into the pot, stirring all the while, and cook until slightly thickened.
STIR IN THE FISH and cook gently 2-3 minutes or until fish is just cooked through and opaque. Remove from heat. Taste and adjust seasonings. Fish out the piece of cheese rind, if you've used one; discard. Serve hot in the warmed bowls garnished with reserved parsley and grated Parmigiano-Reggiano along with a few more grates of pepper.STORE two days in the fridge, well-covered. Reheat over low flame without boiling. Do not freeze.