Add lentils to a small pot with 1 1/2 cups water. Bring to a boil, cover with a lid and reduce heat. Simmer until they are tender (15-20 minutes). Store in the fridge until ready to use.

To make the dressing, whisk together Dijon mustard, red wine vinegar, and salt and pepper. In a steady stream, whisk in the olive oil. Store in the fridge until ready to use.

Cut squash in half and scoop out seeds. Bake flash side down for 35 minutes at 400°F until soft and tender. Store in the fridge until ready to use.