Pierce potato (or potatoes) 4-5 times per side with a fork. Place in a shallow bowl of water in the microwave and cook 5 minutes on high. Flip potato(es) over and cook an additional 5 minutes. Carefully remove from microwave and strain out the water. When the potatoes are cool enough to handle but still slightly warm, peel off the skin and cut them into rough 2" slices. Place in a medium sized bowl along with 2 tablespoon butter and mash until mostly smooth. Set aside.
Combine turmeric, coriander, cumin, cardamom, and cinnamon in a small bowl and set aside.
In a small saucepan melt 2 tablespoon butter over medium heat until it starts to bubble and fizz. Add minced garlic and ginger and stir, cooking to soften, about 1 minute, then add the spice blend from the previous step and stir until combined.
Add the tomato sauce and continue stirring to evenly incorporate all the ingredients. When the sauce is one uniform color, add the greek yogurt and stir again until no visible white streaks of yogurt remain.
Season with salt and pepper, and adjust spices to taste.
Pour the sauce over the mashed potatoes along with the vegetable bouillon paste and mash until fully combined and cohesive with no visible dark streaks of sauce or light streaks of potatoes. Add salt and pepper to taste.Chill for at least 20 minutes before scooping.