Slow Cooker Ghormeh Sabzi (Persian Beef Stew)

Name: Slow Cooker Ghormeh Sabzi (Persian Beef Stew)
Cuisine: Asian, Middle Eastern
Ingredients: 2 TBSP olive oil; 1 yellow onion, diced; 3 medium garlic cloves, minced; 1 pound boneless chuck roast, cut into 1-inch pieces; salt & freshly ground black pepper; 1 tsp ground fennel seed; 1 tsp turmeric; 1 tsp ground sumac; 1 bunch fresh parsley, finely chopped; 1 bunch fresh cilantro, finely chopped; 1 bunch green onion, green parts diced; 2 cups water; 1/2 cup dried red kidney beans, thoroughly rinsed; steamed basmati rice or tahdig