I'm a big fan of crockpots, as you're probably learning. Being able to chuck in a bunch of ingredients, leave for 8 hours and come back to a delicious dinner hits all the right notes with me. You can make some seriously affordable and amazing dishes with those gadgets.
Tarragon Chicken
You want a cheap, seemingly fancy meal that'll impress a crowd? Try this one out. The chicken will fall right off the bone into your mouth... er... Well, let's just say it's tender. Serve it over rice or noodles with some veggies for a seriously filling dinner.
If you spend some time pricing meat cuts in your grocery store, you might have overlooked the amazingly cheap chicken leg quarter. I can regularly grab a 10 lb (that's not a typo, folks) bag of them for $5.60 at Wegman's. I'm sure your grocery store (or butcher if you're one of those lucky types) will hook you up proper. These are absolutely perfect for the crockpot and ideal for this dish.
To save some time in the morning, slather the mustard mixture on the chicken pieces the night before. You can toss the crock for your pot right into the fridge till the next day. I usually chop the garlic and tarragon at the same time and just store them in a bowl near the crock. You'd probably be fine sprinkling that on the chicken overnight and just pour on the chicken stock in the morning.
If the sauce sounds daunting, don't sweat it. It's actually very quick and easy. If you've never worked with corn starch, I do recommend whisking as you add it since that stuff has a habit of setting up at an aggravating speed.
For the folks who don't like the concept of corn starch or are allergic to it, here you go: Substitutions galore! Try potato flour for a change of pace. You can even use it to coat chicken for frying for a light, crispy texture. It's also a kindness to those who want or need to avoid gluten.