In a skillet over medium heat, brown the ground beef for about 5 minutes.

Add the chopped onion and bell pepper, cooking until softened, about 3-4 minutes.

Pour in the Sloppy Joe sauce and stir well. Let this mixture simmer for 5 minutes.

While the Sloppy Joe mix is simmering, spread butter on one side of each slice of bread.

On the unbuttered side of four slices, layer cheese followed by a generous scoop of the Sloppy Joe mixture.

Top with another slice of cheese and the remaining bread, buttered side out.

In the same skillet, heat over medium heat.

Carefully place the sandwiches in the skillet and grill for about 4-5 minutes on each side or until golden brown.

Once golden and melted, remove from the skillet and let cool for a minute. Slice in half and serve warm.