Swiss Chard & Artichoke Pizza

taken with slight modifications from:
http://foodiefarmgirl.blogspot.com/2009/01/swiss-chard-and-artichoke-white-pizza.html

Although this calls for swiss chard, I have used kale and spinach in its place and loved it.

Pizza dough (use your favorite or you can find pre-made dough at the store)
6 to 8 ounces mozzarella, thinly sliced or shredded

3 Tablespoons olive oil
1 cup finely chopped onion (about 5 ounces)
4 to 6 cloves garlic, minced
1 bunch Swiss chard (about 12 ounces or 4 cups packed of leaves), stalks discared and leaves chopped small
1 14-ounce can artichoke hearts (packed in water), drained and rinsed, chopped into small pieces
1 teaspoon Worcestershire sauce
3/4 cup freshly grated Pecorino Romano or Parmesan cheese

Heat olive oil in a 4-quart or larger pot. Add onion and cook, stirring frequently, until soft, about 6 to 8 minutes. Add garlic and cook, stirring frequently, 2 minutes; do not let garlic brown.

Stir Swiss chard leaves and chopped artichoke hearts into onion mixture. Cover and cook, stirring occasionally, about 10 to 12 minutes. Stir in the Worcestershire sauce. Remove pan from heat and let chard mixture cool slightly, and then stir in Pecorino Romano/Parmesan. Alternatively, let the mixture cool completely, mix in cheese, and then refrigerate up to 2 days.

Shape the pizza dough on a piece of unbleached parchment paper and set it on a pizza pan. Spread the chard mixture evenly over the dough. Top with mozzarella. Bake pizza until the crust is golden and the cheese is starting to brown - about 30 minutes.