Preheat the oven to 350 degrees F.
Place the diced tomatoes in a colander. Sprinkle with the onions, basil, and House Seasoning, and toss to coat. Allow to drain, stirring occasionally. Fill each phyllo shell with a scant tablespoon of the tomato mixture. Stir together the mozzarella and mayonnaise. Frost the top of each shell with a scant tablespoon of the mozzarella mixture. Sprinkle each shell with 1/4 teaspoon of bacon pieces. Bake the filled shells for 10 to 12 minutes. Serve hot. These may be prepared ahead of time and refrigerated until serving time.
Mix ingredients together and store in an airtight container for up to 6 months.