Combine butter and 2 tablespoons seasoning in a small bowl. Mix well. Spread on one side of each slice of bread.
Top unbuttered side of 6 slices of bread with a slice of cheddar cheese, Havarti cheese, 2 ounces of turkey and sliced tomatoes. Sprinkle tomatoes with additional seasoning if desired. Top with remaining bread, buttered side out.
Heat skillet or panini maker on medium high heat. Grill 3 to 5 minutes, turning once, until bread is well toasted and cheese has melted. Serve immediately with fresh vegetables and a favorite dip.