1/2 pound fresh chorizo or bulk spicy pork sausage
10 bacon strips, diced
1 large sweet red pepper, finely chopped
1 medium onion, finely chopped
2 garlic cloves, minced
1/4 teaspoon crushed red pepper flakes
1/8 teaspoon cayenne pepper
1/2 cup grated Parmesan cheese
6 large portobello mushrooms (4 to 4-1/2 inches)
Soak planks in water at least 1 hour. In a large skillet, cook chorizo and bacon over medium heat 10-12 minutes or until chorizo is fully cooked and bacon is crisp. Remove with a slotted spoon; drain on paper towels. Discard drippings, reserving 1 tablespoon in pan.
Add pepper and onion to drippings; cook and stir over medium-high heat 3-4 minutes or until tender. Add garlic, pepper flakes and cayenne; cook 30 seconds longer. In a large bowl, combine meat mixture, vegetable mixture and cheese; set aside.
Remove and discard stems from mushrooms; with a spoon, scrape and remove gills. Fill caps with meat mixture.
Place planks on grill rack over direct medium heat. Cover and heat 3-4 minutes or until light to medium smoke comes from the plank and the wood begins to crackle. (This indicates the plank is ready.) Turn planks over; place mushroom caps on planks. Grill, covered, over medium heat 8-10 minutes or until mushrooms are tender.