Preheat the oven to 325 degrees . Scatter the bread on a baking sheet and season with the herbes de Provence. Toast in the oven until golden, 10 to 12 minutes. Set aside.
In a large nonstick skillet, heat 1 tablespoon EVOO, 1 turn of the pan, over medium-high heat. Add the sausage and cook until the fat renders, 2 minutes. Add the chicken and cook for 3 minutes, then add the shrimp and cook until pink and firm, 3 to 4 minutes. Season with salt and pepper. Set aside.
In a second skillet, heat the remaining 1 tablespoon EVOO, 1 turn of the pan, over medium-high heat. Add the bell pepper, onion, celery and garlic, season with salt and pepper and cook until the vegetables are tender, 7 minutes.
Add the reserved bread cubes and vegetables to the sausage mixture and toss to combine; set the vegetable skillet aside. Stir in 1 cup chicken broth and lower the heat to low.
In the vegetable skillet, melt the butter over medium heat. Whisk in the flour and cook for 1 minute. Whisk in the remaining 2 cups chicken broth and the hot sauce, season with salt and pepper and cook until the gravy is thickened, 1 to 2 minutes.
Pile the stuffing into shallow bowls and top with the gravy, scallions and thyme.