I reduced the mustard by half (too much) and left out the marinade and tempeh part. I used just potatoes and the cheese sauce. Excellent! My non vegan mother loved it, and my lactose intolerant sister loved it! It's like cheesy Au Gratin potatoes. I made a batch of just the sauce and thickened it. Poured it over small gluten free noodles and it was great as well! You can add peas and a can of tuna and have an amazing filling dish. My sister loves this even more!
This was ok but considering the prep time I don't think I'll make it again. A bit bland for my taste.