Press the extra firm tofu with a heavy object for 10 minutes to remove excess moisture and then cut into half-inch cubes.
Heat the avocado oil in a large non-stick skillet over medium-high heat until shimmering.
Add the tofu cubes to the skillet and sear until golden brown and crispy on all sides, which should take approximately 8 minutes.
Add the broccoli florets and a tablespoon of water to the skillet, then cover with a lid for 2 minutes to lightly steam the vegetables.
Stir in the cooked brown lentils, tamari, garlic powder, onion powder, sea salt, and black pepper.
Cook the mixture for another 3 minutes, stirring frequently until the lentils are heated through and the flavors are well combined.
Remove the skillet from the heat and fold in the fresh baby spinach, allowing the residual heat to wilt the leaves.
Transfer the mixture to a bowl and sprinkle with nutritional yeast and hemp hearts before drizzling with fresh lemon juice.