Blackened Leftover Meatloaf with Microwave Tomato Gravy

Ingredients

• 1/2 to 1-inch thick-sliced leftover meatloaf (slice when chilled)
• Blackening Spice Mix or your favorite Cajun rub
• 1 16-oz can diced tomatoes
• 1 tablespoon all-purpose flour
• 1 teaspoon granulated sugar
• 1/4 teaspoon sea or table salt
• Freshly ground pepper
• 1 teaspoon apple or white vinegar
• 1 teaspoon Worcestershire sauce
• 2 teaspoons prepared mustard
• 1 tablespoon butter (optional)