slow cooker pesto chicken and sweet potatoes

I now teach 2 days of piano lessons until dinner time so I'm trying to make more slow cooker meals, but I'm just not very good at it.  I guess I need to read more on 365 crockpot.  I tried another recipe from there today, but ended up with dry chicken - very dry.  I overcooked it - it is totally my fault.  Why do I not follow directions?  It was supposed to cook on high for 4-5 hours, but I left it 5 1/2.  I thought that would be ok because my chicken was frozen and my sweet potatoes were a bit large, but it wasn't.  The flavor of the meal was good, and the chicken was redeemable when soaked in the juices from the bottom of the slow cooker.  We topped the sweet potatoes with butter and cinnamon, but even they were overdone.  If you are a better crock pot cook than I am, this could be good. :)  It was also pretty simple to make.  I actually tried it because it was a layered meal in the crockpot.  The idea intrigued me.  Too bad it didn't work better for me.  I think that is part of the reason I overdid it.  I couldn't see the chicken and I could tell nothing just by looking at the sweet potatoes.  Live and learn.

Ingredients

Pesto

• 1/4 cup olive oil
• 2 Tablespoons lemon or lime juice (I used lime juice)
• 4 garlic cloves
• 2 cups fresh basil
• 2 Tablespoons pinenuts, walnuts or sunflower seeds (I used walnuts)
• 1/4 teaspoon pepper
• 1/4 teaspoon salt

Meal ingredients

• 4 chicken thighs or breast halves (I used 1 lb 9 oz. of breast halves - may have only been 3, they were in a big block frozen when I tossed them in the crockpot.)
• sliced mozzarella cheese (enough slices to cover the chicken)
• aluminum foil
• 4 small sweet potatoes, washed well, skin on (Mine were larger than I wanted, but the smallest they had at the store so I chopped them in half.  Not sure that was such a good idea.  They blackened on the edges.

Directions

1. Combine all pesto ingredients in a food processor or blender and puree.  When it is liquefied, taste and season if necessary.
2. Place the chicken in the bottom of a 6 quart slow cooker.  Top with mozzarella cheese.  Pour pesto evenly on top.  Cover with aluminum foil.
3. Clean sweet potatoes well and place on top of the foil.  Cover and cook on high for 4-5 hours, or on low for 6-7.