01 - Heat a large nonstick skillet or griddle over medium heat.
02 - Whisk together honey mustard and mayonnaise in a small bowl until smooth.
03 - Open each roll and spread honey mustard mixture on cut sides of both halves. Layer bottom half with cheddar cheese half, add ham half if desired, and close with top bun.
04 - Spread softened butter evenly over the outside top and bottom of each assembled roll.
05 - Place rolls butter-side down in preheated skillet. Press gently with spatula and cook for 2-3 minutes per side until golden brown and cheese has melted.
06 - Remove from heat and immediately sprinkle with poppy seeds and chives if using. Serve warm.