Sweat the aromatics: Heat the olive oil in a large, heavy-bottomed pot over a medium heat. Add the diced onion and cook for 5-7 minutes until it turns translucent and soft, and you can smell its sweet, mellow fragrance. The onions should look glossy, not brown.

Brown the beef: Add the beef mince to the pot, breaking it up with a wooden spoon. Cook for 6-8 minutes until it is no longer pink and has started to brown around the edges. You'll hear a satisfying sizzle, and the colour should shift from pale pink to a rich, deep brown.

Bloom the spices: Stir in the minced garlic, tomato purée, dried oregano, dried basil, and chilli flakes (if using). Cook for 1 minute, stirring constantly. The aroma will hit you immediately—pungent, savoury, and intensely herby. The tomato purée will darken slightly as it cooks.

Build the broth: Pour in the tinned chopped tomatoes and the beef stock. Stir everything together, scraping the bottom of the pot to release any browned bits. Bring the soup to a gentle simmer—you should see small bubbles breaking the surface, not a vigorous boil.

Simmer to perfection: Reduce the heat to low and let the soup simmer uncovered for 15-20 minutes. The liquid will reduce slightly and thicken. Taste it; the flavours should meld into a harmonious, tangy-savoury profile. Season with salt and black pepper to your liking.

Prepare the cheese toasts: While the soup simmers, preheat your grill to high. Toast the bread slices lightly on both sides until they are firm but not deeply coloured. This step is crucial—it prevents the bread from turning into a soggy mess under the molten cheese.

Assemble the bowls: Ladle the hot soup into four oven-safe bowls, filling them about three-quarters full. Place a slice of toasted bread on top of each bowl, pressing it down gently so it sits level with the rim.

The grand finale: Divide the torn mozzarella evenly over each slice of bread, making sure to cover the edges so they melt and drip down into the soup. Place the bowls under the hot grill for 2-3 minutes. Watch closely—the cheese will bubble, turn golden in patches, and begin to brown. The smell of toasted bread and melted cheese filling your kitchen is the signal that it's ready.

Garnish and serve: Carefully remove the bowls (they will be very hot). Tear fresh basil leaves over the top, drizzle with a little extra-virgin olive oil, and serve immediately. The contrast between the hot, crunchy cheese crust and the rich, smooth soup is pure magic.