Pecan-Stuffed Mushrooms - cooking recipe

Ingredients

24 baby portabella mushrooms, with stems (1 1/2-inch to 2-inch wide)
2 tablespoons olive oil, plus additional for greasing dish (original recipe called for unsalted butter-use if you wish or use 1/2 butter, 1/2 olive oil)
1 -2 large garlic clove, minced
1 1/2 teaspoons finely chopped fresh oregano (or 1/2 tsp. dried)
1 cup pecans, finely chopped (4 oz.)
2 tablespoons breadcrumbs
1/2 teaspoon salt (or more to taste)
1/4 teaspoon black pepper
1/3 cup half-and-half
2/3 cup heavy cream
parsley, chopped to garnish

Preparation

Put oven rack in middle position in oven and preheat to 400\u00b0F.
Trim ends of mushroom stems and separate caps and stems, reserving both. Arrange caps, stemmed sides up, in a buttered 13\"x9\" shallow baking dish.
Finely chop stems(or process in food processor), then cook with garlic and oregano in butter(or olive oil) in a 10\" heavy skillet over medium heat, stirring frequently, until lightly browned, about 5 minutes. Stir in pecans, bread crumbs, 1/4 teaspoon salt, and 1/8 teaspoon pepper and cook, stirring frequently, 1 minute. Stir in 1/3 cup half and half and bring to a simmer, then remove from heat.
Sprinkle insides of caps with remaining 1/4 teaspoon salt and 1/8 teaspoon pepper, then divide filling among the caps.
Drizzle mushrooms with the 2/3 cup cream and bake until filling is browned and caps are tender, about 30 minutes. Sprinkle over parsley to garnish. Serve mushrooms drizzled with pan juices.
To make ahead:
Stuffed mushrooms can be put together, but not baked, 1 day ahead and chilled, covered. Bring to room temperature before baking.