Brown the Sausages: Place your large frying pan or skillet over a medium-high heat and add the olive oil. When the oil shimmers, carefully add the sausages. Cook for 6-8 minutes, turning occasionally, until they are a deep, even golden brown on all sides. You'll hear a satisfying sizzle, and the kitchen will smell gloriously savoury. Once done, transfer them to a plate — they will finish cooking later.

Sweat the Aromatics: Reduce the heat to medium. Add the sliced onions and peppers to the pan. Stir them with a wooden spoon, scraping up those browned bits from the bottom of the pan. Cook for 5-7 minutes, until the onions become translucent and the peppers soften, releasing a sweet, fragrant aroma. The pan should look moist, not dry.

Add the Garlic and Herbs: Stir in the minced garlic, dried oregano, dried thyme, and red pepper flakes (if using). Cook for just 30 seconds, stirring constantly, until the garlic is incredibly fragrant but not burning — you'll smell it immediately. This step is quick, so don't walk away.

Build the Sauce: Pour in the chopped tomatoes and beef stock. Add the tomato purée and stir well to combine. Bring the mixture to a gentle bubble — you'll see small, lazy bubbles breaking the surface. Season with a pinch of salt and a grind of black pepper.

Return the Sausages: Nestle the browned sausages back into the pan, partially submerging them in the sauce. Reduce the heat to low, cover the pan with a lid, and let everything simmer gently for 15 minutes. The sauce will thicken slightly, and the sausages will cook through completely. You'll see the sauce turn a richer, deeper red.

Finish and Serve: Remove the lid and let it simmer for another 2-3 minutes to allow the sauce to reduce a little more. The peppers should be tender but still hold their shape. Taste the sauce and adjust seasoning if needed. Garnish with fresh basil leaves and serve immediately.