My colleague Shanti suggested that I tackle the Slow Food $5 Challenge. Basically, you pledge "to share a fresh, healthy meal that costs less than $5 -- because slow food shouldn't have to cost more than fast food."

I decided to use as many vegetarian ingredients from the Union Square Greenmarket as I could, because it's hard for me to get excited about shopping at this time of year -- there are tables of root vegetables, the last of the stored apples, and some greenhouse greens. Oh, and it is cold outside. On some days, very cold. This would be a fun extra inspiration while I shopped.

But there's another reason I wanted to avoid meat. I've been following the FDA's decision to ignore the issue of antibiotic use in livestock. I mean, I'm a procrastinator, but taking 35 years to do something wrong is not only shameful, it has helped promote the rise of superbugs. Five U.S. presidents have come and gone while the FDA has continued to duck its responsibility to protect our health.

The threat of superbugs is no joke. Recently researchers found drug-resistant Staph aureus, which can cause anything from rashes to fatal pneumonia, in nearly half the meat samples they tested from 26 grocery stores in five U.S. cities.

To protect themselves, consumers should:

• Buy antibiotic-free meat, poultry, and eggs: Look for products labeled USDA Certified Organic, American Grassfed Certified, Animal Welfare Approved, and Certified Humane. Some major brands -- such as Applegate Farms, Murray's Chicken, and the Chipotle restaurant chain -- will not buy animal products that have been fed or treated with antibiotics.
• Prepare and cook your meat safely, following USDA's recommended practices.
• Explore a more varied diet and different sources of protein.

This last point is the ulterior motive for my choice of recipes in the Slow Food challenge. I'm preparing a Spanish tortilla, which is an egg and potato frittata not to be mistaken with Mexican tortillas. Tortillas are sold all over Spain in restaurants, tapas bars, and sandwich shops, and are eaten as snacks or meals. My first memory of a Spanish tortilla was as a sandwich filler in a baguette rubbed with the insides of a cherry tomato, a drip of olive oil, and some salt and pepper. It was love at first bite.

On a recent trip to Spain to visit my friends Tom and Carlos, I mentioned my love of tortillas. Carlos, who is an excellent cook, insisted on teaching me how to make one. I soon realized why none of my prior efforts had ever worked -- I didn't know how to cook the potatoes correctly. Carlos and I added a sprig of rosemary, which is not part of the traditional recipe but a subtle addition that I've loved ever since.

The main ingredients of the Spanish tortilla are extremely simple and can all be found at the farmers' market right now. The most expensive part of the meal is the olive oil, but even accounting for this, I was able to add a simple salad and some wonderful bread from Hot Bread Kitchen while keeping costs under five dollars per person.

Spanish Tortilla

Ingredients

• 4 small-to-medium peeled russet potatoes (about 1 pound to 1 ½ pounds), preferably organic, diced to ½-inch pieces
• ½ onion, diced to ¾ inch pieces
• 2 to 3 cups regular olive oil (strain and reuse it after)
• 1 tsp salt
• 1 sprig rosemary
• 6 extra large Certified Humane eggs
• salt and pepper to taste

1. In medium pot, heat one tablespoon oil on medium high heat and cook diced onion until translucent.
2. Add rest of oil, potatoes, and rosemary. After a few minutes, reduce heat to medium. You want to cook the potatoes thoroughly without deep-frying them, so if oil begins bubbling rapidly, reduce heat further. Stir occasionally to prevent anything from sticking to the bottom. Don't worry if some pieces break (Carlos actually breaks the potatoes instead of dicing them as he feels it make the tortilla taste better). Cook until the potatoes are tender and easily pierced with a fork.
3. While potatoes cook, whisk the eggs and salt in a bowl.
4. Remove rosemary sprig. Strain the potatoes and onions (or use a slotted spoon to remove oil) and mix into bowl with eggs. Make sure to reserve at least one or two tablespoons of the used oil.
5. Warm a 10-inch cast iron skillet of oil over high heat with one tablespoon oil. Once warm, add the egg mixture and all its contents into the pan and stir. Smooth out contents of the mixture in pan and reduce to medium heat.
6. Occasionally give pan a gentle shake on the burner to prevent sticking.
7. When the mixture is almost cooked through, but the top is still runny, you will need to remove and flip the tortilla (before the bottom burns). This can be tricky and they actually sell special plates in Spain for this. Loosen the tortilla with a spatula so that no part of it is sticking to the pan. Then slide the tortilla onto a 12-inch plate (or a pot cover that is larger than your pan), with the uncooked part still facing up.
8. Add a little oil in pan to coat, if necessary.
9. Holding the plate with one hand, invert the pan and place it on top of the tortilla, then with both hands flip the plate and pan at the same time to settle the tortilla upside-down in the pan. Return the pan to medium heat to cook and give it a gentle shake occasionally. Cook about two minutes longer.
10. Slide tortilla out of pan. Serve warm or room temperature.

Anyone else have an idea for the challenge? Or ideas about what to cook from the farmers market this time of year?

Image: Patty Arndt