---
title: Melt in the Middle Meatballs
source:
  name: HelloFresh
  url: https://www.hellofresh.com/recipes/uk-melt-in-the-middle-meatballs-57558e5b4dab7189498b4567
servings: 2
prep time: 15 minutes
cook time: 25 minutes
time required: 40 minutes
difficulty: Easy
allergens:
  - Wheat
  - Milk
tags:
  - Italian
  - Comfort Food
  - Family Friendly
rating: 3.5
rating_count: 833
source_chef: Recipe Development Team
review_highlights:
  - theme: Flavor
    text: Gooey mozzarella center is a hit with kids and adults alike
  - theme: Ease of prep
    text: Simple steps make it a straightforward weeknight dinner
image: "https://images.recipes.furrysalamander.com/Meatball%20Recipes/melt-in-the-middle-meatballs.avif"
---
Wash and dry all produce. Preheat the oven to 400 degrees. Bring a #large pot{} of salted water to a boil. Halve, peel, and finely dice the @red onion{1}. Mince or grate the @garlic{2%cloves}. Cut the @fresh mozzarella{6%oz} into small cubes. Trim and discard the bottom inch from the @baby broccolini{8%oz}.

Heat a large drizzle of @olive oil{3%tbsp} in a #large pan{} over medium-high heat. Add half the red onion and cook, tossing ~{2%minutes}, until softened. Add the @panko breadcrumbs{½%cup}, half the @dried thyme{½%tsp}, and half the garlic and cook for an additional ~{1%minutes}, until fragrant. Season with @salt{1%tsp} and @black pepper{½%tsp}. Transfer the mixture to a large bowl.

Roast the broccolini: Toss the baby broccolini on a #baking sheet{} with a drizzle of olive oil and a pinch of salt and pepper. Place in the oven ~{20%minutes}, turning halfway through, until slightly crispy.

Form the meatballs: Thoroughly mix the @ground beef{16%oz} into the panko mixture along with a large pinch of salt and pepper. Form the mixture into golf ball-sized meatballs. Press 1 cube of mozzarella into the center of each meatball and seal the meat around the cheese. Reserve the extra mozzarella for later.

Add the @spaghetti{8%oz} to the boiling water and cook ~{10%minutes}, until al dente. Heat a large drizzle of olive oil in the same #large pan{} over high heat. Add the meatballs to the pan and sear ~{4%minutes}, rotating to brown on all sides. Remove from the pan and set aside.

Heat a drizzle of olive oil in the same #large pan{} over medium-high heat. Add the remaining onion, thyme, and garlic to the pan. Cook, tossing, ~{2%minutes}, until softened. Add the @diced tomatoes{14.5%oz}, @beef stock concentrate{1%tbsp}, @sugar{2%tsp}, and @water{2%cups} to the pan. Bring to a simmer and season with salt and pepper. Return the meatballs to the sauce to finish cooking through ~{5%minutes}.

Drain the spaghetti and divide between plates. Top with the sauce and meatballs. Roughly chop the broccolini and sprinkle over the plate. Top with any remaining mozzarella and enjoy!