Looking at the lua, the recipe reads this:
{
type = "recipe",
name = "lf-furnace-1",
ingredients = {{"steel-plate", 15}, {"advanced-circuit", 1}, {"electric-furnace", 1}},
result = "electric-furnace",
energy_required = 5,
enabled = false
},
instead of
{
type = "recipe",
name = "lf-furnace-1",
ingredients = {{"steel-plate", 15}, {"advanced-circuit", 1}, {"electric-furnace", 1}},
result = "lf-furnace-1",
energy_required = 5,
enabled = false
},