Brown the beef, onions, and garlic in a frying pan over medium heat, for about 6 to 8 minutes. Drain it.
Toss the bread cubes with the olive oil in a 9” x 13” baking pan. Bake in a 350◦F oven for about 5 to 8 minutes, until they are nearly dry. Add the beef and seasonings (including ½ teaspoon of seasoning salt) to the baking dish and stir it well.
Combine the eggs, remaining ½ teaspoon of seasoning salt, and yogurt in a small dish, mixing well. Pour it over the bread and sausage mixture. Do not stir.
Sprinkle the cheeses over the top of the casserole. Garnish it with a very small amount of basil and garlic granules.
Bake the casserole for about 25 minutes at 350◦F. Refrigerate any leftovers and reheat in the microwave on medium power until they are warm.