3 spinach and gruyere souffle Recipes

unsalted butter, room temperature, plus extra, plain dried breadcrumbs, spinach, trimmed and washed, all-purpose flour, whole milk, grated gruyere cheese, coarse salt, ground pepper, eggs, separated, egg whites

olive oil, bacon cut 1/2 squares, freshly-grated parmesan cheese, unsalted butter, yellow onion diced, all purpose flour, milk, egg yolks, salt, freshly ground black pepper, egg whites at room temperature, shredded gruyere cheese lightly packed, baby spinach leaves lightly packed