Yes. The Add Ingredient or Sub-recipe picker lists both ingredients and sub-recipes (tick the Sub-recipe filter to show only sub-recipes; each row shows its Type). Nested sub-recipes are handled like ingredients: their cost is scaled by the quantity you enter. A sub-recipe cannot include itself, and when an ingredient's price, trim, allergens or dislikes change, Sprwt walks the whole chain upwards so that every parent sub-recipe that contains it (and their own parents) stays up to date.