Slice the tempeh into half-inch thick strips and whisk together the tamari and half the lemon juice in a shallow dish.
Place the tempeh in the marinade for at least ten minutes to soak up the savory flavors.
Heat a grill pan over medium-high heat and lightly brush with a small amount of oil.
Grill the tempeh for three to four minutes per side until distinct grill marks appear and the edges are slightly crisp.
Drain and rinse the white beans and add them to a small saucepan with the tahini, nutritional yeast, and a splash of water.
Warm the bean mixture over medium heat, then mash with a fork or use an immersion blender until smooth and velvety.
In a separate skillet, heat the olive oil and add the minced garlic, sautéing for thirty seconds until fragrant.
Add the green beans to the skillet with a splash of water, cover, and steam-sauté for five minutes until tender-crisp.
Plate the creamy bean mash first, top with the grilled tempeh, and serve the garlic green beans on the side.
Finish the dish with the remaining squeeze of fresh lemon juice for a bright pop of acidity.