1. Pre heat oven to 350 degrees F.
2. Trim green beans and add to a pot of boiling salted water along with sliced lemons. Cook for about 10 minutes until barely cooked. Drain.
3. In a large saute pan, saute onions, mushrooms and garlic in butter 5 to 6 minutes until softened and cooked. Remove from heat.
4. To saute pan, add condensed soup, green beans, seasonings and 1/2 cup of fried onions. Stir to mix
5. Transfer to a buttered 2-quart baking dish. (Can be prepared to here up to 1 day ahead and refrigerated.)
6. Bake for 20 minutes, top with cheese and remaining fried onions. Bake another 10 minutes, or until the casserole is hot and bubbly and the cheese is melted.