This requires some lead time, but it's worth it, and it winds up as something I'd qualify as easy.

Get one of those oven bags for easy cleanup.

2 lb London broil
5 small turnips
3 stalks celery
2 cup carrots/zucchini/cauliflower/peppers (depending on tastes & carbs)
1/2 small onion

Cut vegetables into bite size pieces and put them and the meat into something to marinate overnight. This is where the bag comes in really handy. Mix it all up with:

1 cup Italian dressing

I used Paul Newman's, but use full fat with real spices!

Then marinate for 6-24 hours in the refrigerator. (I like to set it up the night before and make the next night easier.)

Bake at 350 for 1 hour & 15 minutes.

For a south of the border flavor, vary the marinade by using salsa or low sugar teriyaki sauce instead.