Cook the vegetables first. Heat 2 teaspoons oil in skillet over medium heat. Add vegetables and cook for 3-4 minutes, until softened. Add seasonings and stir to incorporate. Set aside to cool.
In a mixing bowl, combine all the dry ingredients.
In a large mixing bowl, combine all the wet ingredients. Add the vegetables and combine.
Add the dry ingredients into the wet ingredients. Be careful not to over mix. Use a spatula (instead of a whisk) to gently stir together. The less you stir the mixture, the lighter and fluffier your muffins will be. Note that the batter will be thick.
Divide batter evenly into a greased, lined or silicone 12-cup muffin pan. Bake for 20-22 minutes, or until the inserted toothpick comes out clean. Allow the muffins to cool for 3-5 minutes before transferring to a wire rack to cool completely.
Take all the cold ingredients out of the refrigerator at least 15 minutes prior to cooking - milk, yogurt, eggs
Use a spoon to scoop the flour into the measuring cup rather than scooping the flour out of the container or bag with your measuring cup.
See FAQ section above for best substitute for white whole wheat flour.
Do NOT over mix the batter. Stir until everything is just combined. It is supposed to be thick and lumpy.