Heat the vegetable oil in a large frying pan over medium heat. Add the chopped onion and green bell pepper. Sauté for 4 to 5 minutes until softened and just beginning to colour. Stir in the minced garlic and cook for 1 minute more. This base builds the classic depth of flavour.

Add the minced beef to the pan, breaking it apart with a wooden spoon. Cook for 6 to 8 minutes, stirring occasionally, until fully browned and no pink remains. Drain off excess fat for a cleaner, more balanced sauce.

Stir in the tomato ketchup and tomato purée. Mix thoroughly so the beef is fully coated. These two elements provide body and sweetness essential to a traditional Sloppy Joe.

Add the Worcestershire sauce, yellow mustard, brown sugar, salt, and black pepper. Stir well to incorporate. These seasonings lend tang, umami, and mild heat, balancing the sweet tomato base.

Pour in the water and bring everything to a gentle simmer. Reduce the heat to low and let the mixture bubble gently for 12 to 15 minutes, stirring occasionally. The sauce should thicken and cling to the meat without being dry.

While the mixture simmers, split the sandwich buns and toast them lightly in a dry pan or under a grill. This adds texture and prevents sogginess from the saucy filling.

Once the sauce has thickened, give it a final taste. Adjust salt, pepper, or mustard as needed. The mixture should be moist but not dripping, with bold, savoury flavour.

Spoon a generous portion of the meat mixture onto the bottom half of each toasted bun. Add optional toppings such as sliced pickles or cheese, then cap with the top half of the bun.

Serve the Sloppy Joes hot, preferably with a side of crisps, fries, or a crunchy slaw. This dish is best enjoyed fresh from the stove when the buns are warm and the filling is steamy.

For a visually appealing plate, wrap the sandwich in parchment for a diner style look, or pair it with a gherkin spear. A touch of hot sauce on the side lets diners adjust the heat to taste.