Place lentils in a medium pot and cover with water. Add bay leaf and half of your onion, left whole. Bring to a boil and turn heat down to a simmer. Let simmer for 15 min, until lentils are slightly tender. Set aside.
Place tomatoes and chipotle pepper in blender, and process until smooth. Set aside.
Place olive oil into a large pot and set over medium heat. Add ¼ of an onion, finely chopped, and sweat for 2-3 minutes. Add minced garlic and sweat for 3 minute more.
Drain lentils and reserve cooking liquid. Mash the lentils with a fork to break them up a bit.Pour lentils into pot and stir to combine with onion and garlic.
Pour the tomato-chipotle mixture into the pot and let cook for 2 min. or until you notice that the tomato puree is changing into a dark red color.
Add 3 cups of the lentil cooking liquid, diced carrot and potato, cumin, oregano, and season to taste.
Bring to a simmer and cook until vegetable are tender, about 20 min.
If the picadillo seems too dry, feel free to add more cooking liquid as needed. Omit the chipotle pepper to make this recipe kid-friendly.