Combine the monkfish with the wine in a flat glass or porcelain dish just large enough to hold the fish and set aside.
In a medium large skillet, heat 1 tablespoon of olive oil until fragrant.
Add the sausage pieces and saute them over medium-high heat for 4 to 5 minutes, turning often to color all sides.
Add another tablespoon of oil, stir in the onion and fennel, and saute them for 1 to 2 minutes.
Stir in the garlic, cover, and adjust the heat to medium to sweat the vegetables until softened, about 10 to 12 minutes.
Stir occasionally.
Add the saffron to the heated stock to soften.
Add the last tablespoon of olive oil to the vegetable mixture and stir in the rice.
Turn the heat up to high, pour in the hot broth and saffron, add the thyme, and stir to blend.
Cover the pan and adjust the heat down so that the liquid slowly simmers.
After 15 minutes, add the monkfish, wine, and tomatoes and continue simmering uncovered until almost all the liquid has evaporated, about 5 to 7 minutes.
Turn the fish pieces to cook evenly.
Stir in the olives, peas, salt, and plenty of pepper and taste for seasonings.
Simmer just 1 or 2 minutes longer.
The paella may be served immediately.
However, it will keep for at least 1/2 hour partially covered over very low heat.