Preheat oven to 350ºF.
Melt butter in a small bowl and add 1 teaspoon of minced garlic.
Generously butter a 12-cup muffin tin, reserving some butter to brush muffin tops.
Combine flour, baking powder, baking soda, and salt in a bowl and mix together.
Combine egg, milk, sour cream, vegetable oil, and garlic in a separate bowl and whisk together.
Pour wet ingredients into the dry ingredients bowl. Lightly mix together before adding cheese, bacon, sun-dried tomatoes, and kalmata olives. Stir together all of the ingredients as few times as possible, just enough to incorporate flour.
Divide muffin batter between muffin cups, filling batter to rim of muffin tin.
Brush tops with butter and bake for about 25 minutes, or until the muffins are golden brown.
Let muffins cool slightly, then remove from muffin tin and place on cooling rack. Serve warm. (Muffins can also be stored in the refrigerator for several days or frozen for a couple of months.)
Cheese, bacon, sun-dried tomatoes, or kalamata olives can be substituted for other ingredients. Swiss, feta, diced ham, or cooked vegetables such as spinach and mushrooms are all great options.