Preheat the oven to 275°F. Add the Goldfish to a mixing bowl, pour over the melted butter, and sprinkle with the celery salt, garlic powder, Italian seasoning, and black pepper. Toss well to coat, then spread onto a baking sheet. Bake for 15-20 minutes, until warm and lightly golden. Remove from the oven and set aside.
While the Goldfish bake, heat the olive oil and butter in a large pan over medium heat. Add the onion and cook for 3-4 minutes, until softened and translucent. Stir in the grated broccoli stems and cook for another 2-3 minutes. Add the garlic and cook for 1 minute, just until fragrant.
Add the dry pastina and cook for 2-3 minutes, stirring frequently, until lightly toasted.
Pour in the chicken stock and stir in the finely chopped broccoli florets. Bring to a gentle bubble, then reduce the heat to a simmer. Cook, stirring frequently like a risotto, until the stock is mostly absorbed and the pastina is tender. Add another splash of stock as needed if the pastina needs more time to cook.
Remove the pan from the heat. Stir in the egg yolk until well combined, then add the grated cheddar and stir until melted and creamy.
Serve the pastina into bowls and top with the garlic herb Goldfish, fresh chives, and a drizzle of olive oil!