Convert Query SQL to use in Laravel 5.6

Good afternoon I'm using Laravel 5.6 and I want to make this sql query

select e.id_asignacion,
e.id_item,
e.serie,
id_funcionario,
id_operacion,
i.precio_unitario,
min(nro_valorada) as minimo,
max(nro_valorada) as Fin,
count(e.id_item) as cantidad
from ejecucions e
INNER JOIN inventarios i on i.id_item=e.id_item
INNER JOIN asignacions a on a.id_asignacion=a.id_asignacion
GROUP BY e.id_item,e.id_asignacion,e.serie,id_operacion,id_funcionario,i.precio_unitario;

and convert it into an eloquent format, to be used with Laravel