In a medium pot (or large for 4 servings), heat a drizzle of olive oil on medium-high until hot. Add the pork and sliced mushrooms; season with salt and pepper. Cook, stirring frequently and breaking the meat apart with a spoon, 6 to 7 minutes, or until lightly browned. Carefully drain off and discard any excess oil. Add the chopped garlic and tomato paste. Cook, stirring constantly, 30 seconds to 1 minute, or until combined. Carefully add the worcestershire sauce and 1/4 cup of water (or 1/2 cup for 4 servings). Cook, stirring frequently, 1 to 2 minutes, or until slightly thickened and the pork is cooked through.