Crockpot Shepherds Pie Easiest Comfort Food EVER

Ingredients

• 1 tbsp olive oil (15ml)
• 1 large onion, chopped (approx. 1 cup, 150g)
• 2 carrots, peeled and diced (approx. 1 cup, 150g)
• 2 celery stalks, diced (approx. 1 cup, 150g)
• 1 lb ground lamb or beef (450g)
• 2 cloves garlic, minced
• 1 tbsp tomato paste (15ml)
• 1 tsp dried thyme
• 1/2 tsp dried rosemary
• 1/4 cup all-purpose flour (30g)
• 1 cup beef broth (240ml)
• 1 cup frozen peas (120g)
• 1 cup frozen corn (120g)
• 1 tbsp Worcestershire sauce (15ml)
• Salt and black pepper to taste
• 3 lbs russet potatoes, peeled and quartered (approx. 1.3 kg)
• 1/2 cup milk (120ml)
• 4 tbsp unsalted butter (56g)
• Optional: 1/4 cup grated cheddar cheese for topping