Heat olive oil on medium to medium-high heat in a large Dutch oven.
Once heated, add chopped onion and sauté until translucent, about 6–7 minutes.
Add chopped peppers and mushrooms and sauté for another 6–7 minutes until vegetables start to brown slightly.
Remove to a separate bowl.
Add cubes of seasoned lamb to the stock pot and brown on all sides. You will start to see brown bits on the bottom of the pot. Scrape these to loosen, which will add flavor to your stew.
Add the vegetables back to the pot, and add diced tomatoes, garlic, spices, and bay leaf to the pot.
Turn heat to high and stir ingredients for 1–2 minutes to incorporate flavors.
Add stock (up to 3 containers depending on how much liquid you prefer) and bring to a boil.
Turn heat to low and simmer for 20 minutes before serving.
Remove bay leaf.
Sprinkle with black pepper and fresh cut parsley.