In a medium pot, add 1 tablespoon of butter and the seasonings (minced onions, garlic salt, black pepper, Italian seasoning, and optional paprika). Cook to brown the butter.
Once browned, stir in the tomato soup, heavy cream, and milk until completely combined.
Turn the heat down to low and let simmer until ready to serve.
In a medium frying pan, melt the remaining butter and the garlic completely.
Place one slice of bread in the pan and top with the cheese. Let sit for a few minutes so the steam can heat and melt the cheese.
Place the second slice of bread on top. When the bottom slice is golden brown, flip the sandwich and cook until the other side reaches your desired color.
Turn off the stove and serve the sandwich with the soup.