Cheesy Beef Mac + Cheese - Canada's Food Island

Ingredients

• 1 lb shell pasta
• 1 lb PEI ground beef
• 1 large onion, diced
• 2 garlic cloves, finely minced
• 1 green bell pepper, medium dice
• 0.5 lb cremini mushrooms, sliced
• 6 tbsp unsalted butter, divided, plus extra for buttering ramekins
• 0.25 cup flour
• 4 cup whole milk
• 2 tsp dijon
• 3 cup grated cheddar, divided
• 1 cup panko
• 2 green onions, finely sliced