SpellBrewery

$ file *
SpellBrewery:                    ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 2.6.32, BuildID[sha1]=0ee68cb419f7329a3bd027c947654385d416143a, not stripped  
SpellBrewery.deps.json:          JSON data
SpellBrewery.dll:                PE32 executable (console) Intel 80386 Mono/.Net assembly, for MS Windows
SpellBrewery.runtimeconfig.json: JSON data

$ strings SpellBrewery | grep -i dll
This executable is not bound to a managed DLL to execute. The binding value is: '%s'  
The required library %s does not support relative app dll paths.
The managed DLL bound to this executable is: '%s'
A fatal error was encountered. This executable was not bound to load a managed DLL.
SpellBrewery.dll

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;


#nullable enable
namespace SpellBrewery
{
  internal class Brewery
  {
    private static readonly string[] IngredientNames = new string[106]
    {
        // ...
    };
    private static readonly string[] correct = new string[36]
    {
        // ...
    };
    private static readonly List<Ingredient> recipe = new List<Ingredient>();

    private static void Main()
    {
      while (true)
      {
        switch (Menu.RunMenu())
        {
          case Menu.Choice.ListIngredients:
            Brewery.ListIngredients();
            break;
          case Menu.Choice.DisplayRecipe:
            Brewery.DisplayRecipe();
            break;
          case Menu.Choice.AddIngredient:
            Brewery.AddIngredient();
            break;
          case Menu.Choice.BrewSpell:
            Brewery.BrewSpell();
            break;
          case Menu.Choice.ClearRecipe:
            Brewery.ClearRecipe();
            break;
        }
      }
    }

    private static void ListIngredients()
    {
      for (int index = 0; index < Brewery.IngredientNames.Length; ++index)
      {
        Console.Write(Brewery.IngredientNames[index] ?? "");
        if (index + 1 < Brewery.IngredientNames.Length)
          Console.Write(", ");
        if (index % 6 == 5)
          Console.Write("\n");
      }
      Console.Write("\n");
    }

    private static void DisplayRecipe()
    {
      if (Brewery.recipe.Count == 0)
        Console.WriteLine("There are no current ingredients");
      else
        Console.WriteLine(string.Join<Ingredient>(", ", (IEnumerable<Ingredient>) Brewery.recipe));
    }

    private static void AddIngredient()
    {
      Console.Write("What ingredient would you like to add? ");
      string name;
      while (true)
      {
        name = Console.ReadLine();
        if (!Enumerable.Contains<string>((IEnumerable<string>) Brewery.IngredientNames, name))
          Console.WriteLine("Invalid ingredient name");
        else
          break;
      }
      Brewery.recipe.Add(new Ingredient(name));
      string str = "aeiou".Contains(char.ToLower(name[0])) ? "an" : "a";
      DefaultInterpolatedStringHandler interpolatedStringHandler = new DefaultInterpolatedStringHandler(41, 2);
      interpolatedStringHandler.AppendLiteral("The cauldron fizzes as you toss in ");
      interpolatedStringHandler.AppendFormatted(str);
      interpolatedStringHandler.AppendLiteral(" '");
      interpolatedStringHandler.AppendFormatted(name);
      interpolatedStringHandler.AppendLiteral("'...");
      Console.WriteLine(interpolatedStringHandler.ToStringAndClear());
    }

    private static void BrewSpell()
    {
      if (Brewery.recipe.Count < 1)
      {
        Console.WriteLine("You can't brew with an empty cauldron");
      }
      else
      {
        byte[] array = Enumerable.ToArray<byte>(Enumerable.Select<Ingredient, byte>((IEnumerable<Ingredient>) Brewery.recipe, (Func<Ingredient, byte>) (ing => (byte) (Array.IndexOf<string>(Brewery.IngredientNames, ing.ToString()) + 32))));  
        if (Enumerable.SequenceEqual<Ingredient>((IEnumerable<Ingredient>) Brewery.recipe, Enumerable.Select<string, Ingredient>((IEnumerable<string>) Brewery.correct, (Func<string, Ingredient>) (name => new Ingredient(name)))))
        {
          Console.WriteLine("The spell is complete - your flag is: " + Encoding.ASCII.GetString(array));
          Environment.Exit(0);
        }
        else
          Console.WriteLine("The cauldron bubbles as your ingredients melt away. Try another recipe.");
      }
    }

    private static void ClearRecipe()
    {
      Brewery.recipe.Clear();
      Console.WriteLine("You pour the cauldron down the drain. A fizzing noise and foul smell rises from it...");
    }
  }
}

    private static void BrewSpell()
    {
      if (Brewery.recipe.Count < 1)
      {
        Console.WriteLine("You can't brew with an empty cauldron");
      }
      else
      {
        byte[] array = Enumerable.ToArray<byte>(Enumerable.Select<Ingredient, byte>((IEnumerable<Ingredient>) Brewery.recipe, (Func<Ingredient, byte>) (ing => (byte) (Array.IndexOf<string>(Brewery.IngredientNames, ing.ToString()) + 32))));  
        if (Enumerable.SequenceEqual<Ingredient>((IEnumerable<Ingredient>) Brewery.recipe, Enumerable.Select<string, Ingredient>((IEnumerable<string>) Brewery.correct, (Func<string, Ingredient>) (name => new Ingredient(name)))))
        {
          Console.WriteLine("The spell is complete - your flag is: " + Encoding.ASCII.GetString(array));
          Environment.Exit(0);
        }
        else
          Console.WriteLine("The cauldron bubbles as your ingredients melt away. Try another recipe.");
      }
    }

ingredient_names = [
    # ...
]

correct = [
    # ...
]

flag = bytes(ingredient_names.index(c) + 32 for c in correct)  
print(flag.decode())

$ python3 solve.py
HTB{y0ur3_4_r34l_p0t10n_m45st3r_n0w}