Generally I marinate portobellos in balsamic and garlic, to use them for sandwiches. They were equally delicious in tacos - the meaty texture and flavor worked well. Cilantro and green onions were the perfect additions. Then I made a spicy cilantro salsa with some tomatoes, onions, and local favorite Clancy's Fancy.
It's crazy it has taken me a month to mention Clancy's, but I live for that stuff. I eat it on EVERYTHING. Three times a day isn't unusual. When I lived in Florida, I'd bring bottles home after every visit to the Mitten. Pass the extra hot, please.