Prepare Pressure Cooker: Heat up your pressure cooker over medium high heat (Instant Pot: press Sauté button and Adjust button once to Sauté More function). Ensure your pot is as hot as it can be (Instant Pot: wait until indicator says HOT).

Brown Ground Beef: Season ground beef generously with kosher salt and freshly ground black pepper. Add 1 tbsp (15ml) olive oil in pressure cooker. Ensure to coat oil over whole bottom of the pot.Add ground beef in pressure cooker. The ground beef will begin to release moisture. At the 5-minute mark, drain & discard the ground beef juice.
Allow ground beef to brown. Stir occasionally until they are slightly crisped and browned (~5 – 7 minutes).

Saute Vegetables: Add diced onion to browned beef and saute for 2 minutes. Add in diced bell pepper and minced garlic, then saute until fragrant (roughly a minute).

Pressure Cook Sloppy Joes: Layer 1 tbsp (15ml) tomato paste, 1 tsp (5ml) dijon mustard, and ¾ cup (188ml) ketchup on top. Do not mix. Close lid and pressure cook at High Pressure for 5 minutes + 10 minutes Natural Release. After 10 minutes, turn venting knob to venting position to release remaining pressure. Open the lid carefully.

Toast Burger Buns: On a skillet, toast burger buns for a few minutes over medium heat.

Reduce and Season: If the Sloppy Joe meat sauce is too runny, give it a quick stir and cook for another few minutes over medium heat (Instant Pot: Press Sauté button). Now is a good time to add in the optional liquid smoke and cayenne pepper if desired. Taste and season with more kosher salt and black pepper if necessary.

Serve: Construct the Sloppy Joes with toasted burger buns. Serve with Tater Tots or your favorite side dishes.