Preheat the oven to 400°. Place all meatball ingredients into the bowl of a food processor and pulse until well chopped and combined, being careful not to overdo it.

Lightly oil a baking sheet or large oven-safe skillet, then roll the chickpea mixture into 1 inch balls (you should get about 30) and arrange on the baking sheet. Lightly brush or spray the balls with oil. Bake until lightly browned, flipping halfway through, about 30 minutes total.

While the meatballs bake, bring a large pot of water to a boil and add the potatoes. Cook until tender and easily pierced with a fork, about 20 minutes. Return the potatoes to the pot and mash with a potato masher.

Stir in the milk and garlic. You can add a bit more milk if you'd like a creamier texture. Season with salt and pepper to taste.

While the meatballs bake and the potatoes boil, coat the bottom of a large skillet with 2 tablespoons of olive oil and place it over medium heat. Add the mushrooms and allow to cook for about 5 minutes, then flip and cook 5 minutes more, until browned on both sides. Transfer to a plate.

Add remaining tablespoon of olive oil to the skillet. Once hot, add the onion. Sauté for about 5 minutes, until translucent. Return the mushrooms to the skillet and sprinkle in the flour, flipping to coat the mushrooms.

Pour in the broth, stirring constantly, then add the tomato paste and soy sauce. Raise heat and bring to a simmer. Lower heat and allow to simmer for about 10 minutes, until it thickens up to a nice gravy consistency. Season with salt and pepper to taste.

Add the meatballs to the gravy and stir a few times to coat with the gravy.

To serve, divide the mashed potatoes onto plates. Top with meatballs and gravy. Sprinkle with parsley. Serve.