Heat a cast iron or oven-safe skillet over medium heat. Once hot add 1 Tbsp olive oil, shallot and garlic. Stir constantly as to not to let it burn.
Add Brussels sprouts, 1/4 tsp each sea salt and pepper and stir. Cook for 3-4 minutes or until tender and slightly wilted and then remove from heat, turning off burner as well.
In a separate bowl mix together sour cream, cream cheese, mozzarella and Parmesan cheese, another pinch of salt and pepper and stir. Add Brussels sprouts mixture to the bowl and stir until well combined.
Use additional Tbsp olive oil to lightly grease the cast iron so the dip does not stick. Spoon dip back into the skillet and bake at 375 for 11-13 minutes or until hot and bubbly.
Serve with veggies, pita, crackers, bread or tortilla chips.