Place the olive oil in a large saucepan, over medium heat.
Add the garlic and onion and cook, stirring frequently, until the onions have softened.
Add the crushed tomatoes, chili powder, cumin, oregano, chipotle (if used), salt, and pepper, and stir well.
Add the water and the lentils, and stir well.
Reduce heat to medium-low and simmer until lentils are cooked through but not mushy, approximately 45 minutes to an hour.
Serve with 1 1/2 tablespoon sour cream and 1/2 ounce Monterey jack cheese per serving.
