Za'atar Roast Chicken - Breaking Matzo

Ingredients

• One 4-1/2 to 5 lb chicken
• 1/2 cup unsalted butter (1 stick), room temperature (to make kosher, use olive oil instead)
• 4 tbsp za’atar (blend of dried spices like thyme and oregano, sumac, sesame seeds and salt)
• 1/2 lemon, sliced
• 1/2 small onion, peeled & sliced
• salt to taste (only use if there is no salt in your za'atar spice blend)