Stir in the minced garlic, dried thyme, cumin, salt, and pepper. Cook for another minute until fragrant.
Add the lentils and vegetable broth to the pot. Bring to a boil, then reduce the heat to a simmer and allow to bubble gently for about 25-30 minutes, or until the lentils are tender.
While the stew is simmering, place the peeled and chopped potatoes in a pot of salted water. Bring to a boil, then reduce to a simmer until tender. Drain and return to the pot. Mash with 1/2 cup milk and 4 tablespoons butter until creamy and smooth.
Spoon the hearty lentil stew over a generous serving of creamy mashed potatoes and enjoy!
Notes
Store leftovers in an airtight container in the refrigerator for up to 3 days or freeze for up to 3 months.