Leftover Spinach Frittata

Ingredients

• 2 cups French baguette cubes (cut into 1/4" cubes from a 7" baguette)
• 1 teaspoon canola oil
• 1 teaspoon butter
• 1 yellow onion, peeled and chopped
• 1 bell pepper (any color), seeded and chopped
• 6 ounces sliced mushrooms (about 2 cups), chopped
• 2 cloves garlic, peeled and minced
• 5 sprigs fresh thyme, leaves picked from stems
• 1 teaspoon salt
• 1 teaspoon ground black pepper