Bring 1½ cups of water to a boil. Add lentils and stir. Cover, reduce heat to low, and simmer for 10-15 minutes, until the lentils are tender.

Brown the ground beef in a skillet over medium-high heat. Add the carrots and ¾ cup of water. Reduce heat to medium and cook for 10 minutes, until the carrots are fork-tender.

Add the cooked lentils and spinach. Stir to combine and cook for 2-5 minutes. Remove from the heat and cool completely before serving.

Store in an airtight container in the fridge.