Repository pattern to execute a stored procedure using Entity Framework

To your generic repository add

public IEnumerable<T> ExecWithStoreProcedure(string query, params object[] parameters)
{
        return _context.Database.SqlQuery<T>(query, parameters);
}

And then you can call it with any unitofwork/repository like

IEnumerable<Products> products = 
             _unitOfWork.ProductRepository.ExecWithStoreProcedure(
             "spGetProducts @bigCategoryId",
             new SqlParameter("bigCategoryId", SqlDbType.BigInt) { Value = categoryId } 
      );