Preheat your oven to 425°F (220°C).

Slice the tops and bottoms off the large yellow onions and remove the outer skins, creating vertical slits down the sides to separate the layers.

Bring a large pot of water to a boil, gently place the prepared onions into it, and simmer for 10-15 minutes.

In a frying pan, heat olive oil and sauté finely chopped shallots and minced garlic until fragrant. Add ground beef and sausage, browning until fully cooked.

Stir in spices, and cook for about a minute until fragrant. Fold in jasmine rice, fresh thyme, chopped tomatoes, and chicken broth, stirring to combine.

Simmer the filling until the broth is absorbed, about 6-7 minutes. Stir in chopped parsley, then remove from heat.

Mix strained tomatoes, remaining broth, and salt in a bowl for the sauce; taste and adjust seasoning.

Spread a layer of sauce in a baking dish, stuff the onions with filling, and arrange them seam side down.

Cover with remaining sauce and seal with aluminum foil. Bake for 30-35 minutes, then remove foil and bake for another 20-30 minutes.

Allow to cool for 10 minutes, then garnish with balsamic glaze, olive oil, and parsley before serving.