Fill a 3-quart pot with water, bring to a boil, and add a dash of salt.
Add the gnocchi to the boiling water and cook over medium heat until they float to the surface, then remove with a slotted spoon to a plate.
In a large skillet over medium heat, melt 1 tablespoon of the butter.
Add the drained gnocchi in batches and fry until golden and light brown on the edges, transferring to a plate as they finish.
Add the remaining 1 tablespoon butter and 1 tablespoon olive oil to the skillet and heat until shimmering.
Add the chopped onion and sauté for 2–3 minutes, stirring often, until softened.
Add the minced garlic and cook until fragrant and the onion is translucent, about 30–60 seconds.
Stir in the dried oregano and Italian seasoning and cook for 1 minute to bloom the herbs.
Pour in the crushed tomatoes, stir to combine, and simmer the sauce for about 5 minutes.
Add the pan-fried gnocchi to the sauce, toss to coat, and simmer briefly to heat through.
Season with salt and black pepper to taste, then serve topped with shredded mozzarella, grated Parmesan, and crushed red pepper flakes.
