Overnight Artichoke & Spinach Egg Bake

Ingredients

• 6 Tbsp. Unsalted Butter, divided
• 6 English Muffins, cubed
• 1 red bell pepper, diced
• 1 yellow onion, diced
• 1/2 tsp. salt
• 4 cloves garlic, minced
• 6 cups packed fresh spinach
• 13.5 oz. can artichokes (, liquid drained and chopped)
• 2 Tbsp. fresh dill or chives ((plus more for garnish))
• 12 Eggs
• 2 cups milk
• 2 cups white cheddar cheese, shredded
• 1/2 tsp. pepper