Preheat your oven to 350 degrees F. This is crucial as a hot oven will ensure your bread gets perfectly crisp while the filling becomes hot and bubbly.
Slice about 2 inches deep through the top of the French bread, and continue to cut a large rectangle. Remove the top of the bread and hollow out 2 inches deep to create a shallow rectangular bread bowl. Set aside. Make sure not to cut all the way through; you want a sturdy base to hold the filling.
In a pan, heat 1 tablespoon of olive oil over medium-high heat. Add onions and sauté for about 5 minutes or until soft. You want them to become translucent and fragrant.
Add the red bell pepper and garlic to the pan, sautéing for one more minute. The aroma should be delightful at this point, filling your kitchen with savory goodness.
Stir in the spinach, pesto, Worcestershire sauce, paprika, salt, pepper, and mayonnaise until well combined. Make sure to cook the mixture just long enough to warm through the spinach, giving it a chance to absorb all those flavors.
Reduce the heat to low and add cream cheese into the mix, stirring until it melts and creates a smooth, creamy texture. This is where the magic happens – the filling starts to become luscious.
Next, stir in sour cream, Parmesan cheese, and cheddar cheese until everything is combined and creamy. You should notice the mixture thickening up beautifully.
Once your filling is ready, spoon the spinach dip into the hollowed-out French bread. Make sure you fill it generously, as this will be the star of the dish.
Top with mozzarella cheese. This will melt into a golden, gooey layer that everyone will love.
Place your stuffed bread onto a baking tray and bake in the preheated oven for 25 to 30 minutes, or until the cheese is melted and slightly golden. Keep an eye on it to avoid burning.
After baking, let the bread sit for approximately 5 minutes to cool. This will help you avoid burning yourself when slicing.
Slice and serve warm, and enjoy the fantastic reactions from your family and friends!
