Sauté the Aromatics: Select the 'Sauté' function on your Instant Pot and set it to high. Add the olive oil. Once shimmering, add the chopped onions and red pepper. Cook for 5-7 minutes, stirring occasionally, until they have softened and the onions are translucent. Add the minced garlic and cook for one more minute until fragrant.

Brown the Mince: Add the beef mince to the pot. Break it up with a wooden spoon and cook until it's browned all over. I find that using a potato masher helps to break the mince into fine, even pieces for a better texture. Drain off any excess fat if necessary.

Bloom the Spices: Turn the 'Sauté' function off or to low. Add the chilli powder, cumin, smoked paprika, oregano, salt, and pepper directly to the meat. Stir continuously for about 60 seconds. This step, known as blooming, toasts the spices and releases their essential oils, making the chili much more aromatic.

Deglaze the Pot: Pour in a small splash of the beef stock (about 50ml) and use your wooden spoon to scrape any browned bits from the bottom of the pot. This is a crucial step to avoid the 'Burn' notice and incorporates a huge amount of flavour into the sauce. This technique is explained well over at Serious Eats.

Add Remaining Ingredients: Add the rest of the beef stock, the chopped tomatoes, tomato purée, and the chopped dark chocolate. Stir everything together well. Do NOT add the kidney beans yet; they can sometimes break down too much under high pressure.

Pressure Cook: Secure the lid on the Instant Pot, ensuring the steam release valve is set to 'Sealing'. Select 'Pressure Cook' (or 'Manual') and set the timer for 15 minutes at high pressure.

Natural Release: Once the cooking cycle is complete, allow the pressure to release naturally for 10 minutes. This helps the meat to stay tender. After 10 minutes, carefully switch the valve to 'Venting' to release any remaining steam.

Finish the Chili: Open the lid. Stir in the drained and rinsed kidney beans and the Worcestershire sauce. Select the 'Sauté' function on low and let the chili simmer for a final 5 minutes to heat the beans through and allow the sauce to thicken slightly. Taste and adjust seasoning if needed.