Heat large skillet or grill pan over medium heat.
In a bowl, mix together cheddar cheese, cream cheese and Dijon mustard. Season with salt and pepper.
Lay out 8 slices of Texas toast. Divide cheese mixture evenly, spreading on each slice. Top 4 of the slices with 1 1/2 sausage patties each. Place the other 4 slices on top, cheese side down. Butter the outsides of the bread and grill on the skillet until golden brown on both sides and cheese is melted.