Add more traditional (American) mixins

INDEX.md

@@ -38,9 +38,12 @@ Marking with a (v) for vegetarian friendly, mostly to make @dansinker and @cjoh
     * [Swiss Chard (v)](base_layers/swiss_chard.md)
     * [Zucchini and Corn Filling (v)](base_layers/zucchini_corn.md)
 * [Mixins](/mixins)
+    * [Cheese (Traditional; US)](mixins/cheese_traditional_us.md)
     * [Corn Salad (v)](mixins/Corn_Salad.md)
     * [Drunken green beans (v)](mixins/drunken_greenbeans.md)
+    * [Lettuce (Traditional; US)](mixins/lettuce_traditional_us.md)
     * [Sweet Potato and Apple Hash (v, substitute butter)](mixins/sweet_potato_and_apple_hash.md)
+    * [Tomatoes (Traditional; US)](mixins/tomatoes_traditional_us.md)
     * [Veggies for Fish Tacos (v)](mixins/veg_for_fish_tacos.md)
 * [Condiments](/condiments)
 	* [Asian Pickled Veggies](condiments/pickled_vegetables.md)

mixins/cheese_traditional_us.md

@@ -0,0 +1,7 @@
+Cheese (Traditional; US)
+======================
+
+A major flavor component of a traditional American taco, select a cheese that's firm and sharp.
+
+* Cheddar (shredded)
+* Jack/Pepper Jack (shredded)

mixins/lettuce_traditional_us.md

@@ -0,0 +1,7 @@
+Lettuce (Traditional; US)
+======================
+
+In a traditional American taco, lettuce serves to add extra crunch and coolness. Favor the bulkier lettuces over leafier fare such as Bibb lettuces or mesclun.
+
+* Iceberg Lettuce (shredded)
+* Romaine Lettuce (shredded; maintain the stalks)

mixins/tomatoes_traditional_us.md

@@ -0,0 +1,8 @@
+Tomatoes (Traditional; US)
+======================
+
+Adding a bit of coolness and moisture, tomatoes are a staple ingredient of the American taco. The better the tomato the more flavor they will impart, but even a sub-sandard grocery store tomato has a place in a traditional taco.
+
+* Tomatoes (diced)
+* Cherry Tomatoes (quartered)
+* Grape Tomatoes (sliced)