In a large nonstick skillet, heat 1 tablespoon oil over medium heat.
Add gnocchi and cook, stirring often, for about 6 minutes, or until plumped and starting to brown.
Remove from heat and transfer gnocchi to a bowl; set aside.
Add the remaining oil and butter to the skillet; heat and stir in the onions. Cook for 2 minutes, stirring often.
Add garlic, brussels sprouts and vegetable broth.
Cover and cook over medium heat for 5 to 6 minutes, or until vegetables are tender.
Stir in tomatoes and chickpeas; season with salt and pepper and bring to a simmer.
Add the previously prepared gnocchi and sprinkle with mozzarella and parmesan.
Cover and cook for 4 to 5 minutes, or until the cheese is melted and the sauce is bubbling.
Remove from heat and serve.