Slice the tempeh into 1-inch uniform cubes to ensure even browning.
Heat the extra virgin olive oil in a non-stick skillet over medium heat and add the tempeh cubes.
Drizzle the tamari over the tempeh and sear for 3-4 minutes per side until the edges are golden and crispy.
Remove the tempeh from the pan and set aside on a plate.
In the same skillet, add the diced onion, carrots, and celery, sautéing for 5 minutes until the vegetables soften.
Stir in the minced garlic and dried thyme, cooking for 1 minute until highly fragrant.
Pour in the cooked green lentils and vegetable broth, then reduce the heat to low.
Simmer the mixture for 6-8 minutes until the broth has mostly reduced and created a light glaze over the legumes.
Season the lentil mixture with sea salt and black pepper.
Fold the crispy tempeh back into the braised lentils and serve immediately while warm.