Sweet Potato Shepherds Pie - Sprinkles & Sea Salt

Ingredients

• 4 pounds sweet potato
• 2 tbsp unsalted butter
• 1/2 tsp salt
• 1 tbsp olive oil
• 1 cup yellow onions, chopped small
• 2 large cloves garlic, smashed
• 1 cup celery, chopped small
• 1 cup carrots, sliced thin
• 2 pounds lean ground beef
• 1 tsp salt
• 1/2 tsp onion powder
• 1/2 tsp dried thyme
• 1 tbsp white all-purpose flour
• 1/4 cup heavy cream
• 1 cup beef stalk
• 1/2 cup peas