I love eating mushrooms in pretty much any way. I use them raw in salads, sautéed or stir fried with noodles and veggies. They're great in pasta, risotto, soup, or omelettes. I love them on pizza, in quesadillas, or grilled on a kabob. A family member makes some of the best stuffed mushrooms I've ever tasted every Thanksgiving. I've had a portobello burger once before and it was good. Mushroom and Swiss burgers were also my favorite back when I ate meat. I've never heard of mushrooms on toast, but it sounds tasty.