What a terrific, filling meatless dish. This could easily be a main dish. It's so quick to make, and that's what makes it taste great; nothing is overcooked. The onions is sauteed, but not soggy, and the spinach is just wilted, not slimy and overcooked. The lemon juice at the end is a real treat. I think seasoned rice vinegar would work in pinch if you had to. I made this just as written, just added a pinch of salt and pepper. Thanx!