|Olive oil/Vegetable oil||1 Tablespoon|
|Yellow onion||1⁄2 Medium, peeled and chopped|
|Garlic||1 Clove (5 gm), peeled and minced|
|Mushrooms||1⁄4 Pound, thinly sliced|
|Chopped cooked spinach||1 Cup (16 tbs)|
|Eggs||4 , lightly beaten|
|Grated parmesan cheese||3⁄4 Cup (12 tbs)|
|Dried marjoram||1⁄4 Teaspoon, crumbled|
|Dried basil||1 Teaspoon, crumbled|
|Black pepper||1⁄4 Teaspoon|
1. Preheat the broiler. Heat the butter and oil in a heavy 8-inch skillet over moderately high heat. Add the onion and garlic, and cook, uncovered, for 5 minutes, or until the onion is soft. Add the mushrooms and cook, tossing, for 1 minute, then add the spinach and cook, tossing, for 1 more minute.
2. In a small bowl, combine the eggs, cheese, marjoram, basil, salt, and pepper. Pour over the vegetables in the skillet, reduce the heat to low, and cook, uncovered, until the eggs are almost set—about 7 minutes.
3. Place the skillet (but not the handle) under the broiler about 3 inches from the heat. Broil for 2 to 3 minutes, or until the frittata is lightly browned. Gut into 4 wedges and serve.