Model collection inside a Model
<p>I am a complete newbie in asp.net mvc. And i'm stuck with some problem and don't yet know how to solve it. I googled, found some useful things, but they haven't helped me with solving my problem. So let's begin with what i have now:</p>

<pre><code>public partial class Dish
    {
        public Dish()
        {
            PortionFood = new HashSet&lt;PortionFood&gt;();
        }    
        [Key]
        public int Id { get; set; }
        [Required]
        [StringLength(50)]
        public string Name { get; set; }
        [JsonIgnore]    
        public virtual DishCategory DishCategory { get; set; }
        [JsonIgnore]
        public virtual ICollection&lt;PortionFood&gt; PortionFood { get; set; }
    }
}
// Food class in a separate file
public partial class Food
    {
        public Food()
        {
            PortionFood = new HashSet&lt;PortionFood&gt;();
        }
        [Key]
        public int Id { get; set; }
        [Required]
        [StringLength(50)]
        public string Name { get; set; }
        public float Proteins { get; set; }
        public float Fat { get; set; }
        public float Carbs { get; set; }
        public float Ccal { get; set; }
        public float? Sugar { get; set; }
        public float? AmountOfWater { get; set; }
        [ForeignKey("FoodCategory")]
        public int IdFoodCategory { get; set; }
        [ForeignKey("FoodConsistencyType")]
        public int IdFoodConsistencyType { get; set; }
        [JsonIgnore]
        public virtual FoodCategory FoodCategory { get; set; }
        [JsonIgnore]
        public virtual ICollection&lt;PortionFood&gt; PortionFood { get; set; }
    }
}
// Portion Food Class in a separate file 
public partial class PortionFood
    {
        [Key]
        [Column(Order = 0)]
        [DatabaseGenerated(DatabaseGeneratedOption.None)]
        [ForeignKey("Food")]
        public int IdFood { get; set; }
        [Key]
        [Column(Order = 1)]
        [DatabaseGenerated(DatabaseGeneratedOption.None)]
        [ForeignKey("Dish")]
        public int IdDish { get; set; }

        public float Amount { get; set; }

        public bool IsDeleted { get; set; }

        public virtual Dish Dish { get; set; }

        public virtual Food Food { get; set; }
    }
}
</code></pre>

<p>PortionFood just specifies what amount of what Food is inside which Dish.
Now i have views for classes Dish and Food, and i am able to add new object of each of these two classes(by filling in the view fields and pressing the button) to DB, i am able to edit an existing Dish &amp;&amp; an existing Food. See list of all existing Food &amp;&amp; Dish objects. 
<br><strong>What i want:</strong><br>
When adding/editing a Dish there must be a possibility to add a PortionFood object releated to current Dish(which we are editing or adding). Just by selecting a FoodId in a dropdown list, setting an amount and clicking the button. The PortionFood object must be inserted to PotionFood collection of related Dish and related Food<br>
How can i implement it?<br> 
If there're any uncretainties write in a comment, and i'll try to make it clear.
<br>Thank's for help!</p>