I love this type of salad. You can mix and match the veggies you like, but one thing is certain it MUST contain petite green peas. Well, I think it must. Commonly called a Seven Layer Salad, I had a couple more layers and, trust me, this salad was none the worst for those additions. I'll give you my general outline of my layers and you can go from there.
One tip I will pass along before we get started is regarding the chopped tomatoes. Before you start layering and assembling the layers, chop the tomatoes first. Place them a few at a time in a mesh strainer placed over a bowl. Sprinkle with salt as you peel and chop the remaining tomatoes. The salt helps to pull the juice out of the tomatoes. You'll be surprised how much juice will be in the bowl when you're ready to use the tomatoes. If you don't take this step, all that juice will be in the bottom of your lovely serving bowl. That would not be good.
As you build your layers, you can fill in the middle with more of the romaine and spinach.
Layer 1: 3 - 4 cups of chopped romaine lettuce
Layer 2: 3 - 4 cups baby spinach
Layer 3: 2 green bell peppers, seeded and diced
Layer 4: 6 hard boiled eggs, peeled and chopped
Layer 5: 1 lb. bacon, cooked, drained and chopped
Layer 6: 4 - 5 tomatoes, chopped and drained well
Layer 7: 1 bunch green onions, thinly sliced
Layer 8: 8 oz. sharp cheddar cheese, grated
Layer 9: 10 oz. frozen green peas, partially thawed
Dressing: 3/4 cup mayonnaise, 3/4 cup sour cream, 1 t. white wine vinegar, 1 T. sugar
Use a trifle bowl, or a clear glass bowl with straight sides so all your beautiful layers will show to their best advantage.
Begin to layer in the other I listed above. Sprinkle the romaine and spinach with salt and pepper. Instead of spreading all your ingredients all the way across the greens, concentrate on placing them against the side of the bowl.
Fill in the middle with the greens as you go. End with a layer of peas that WILL go all the way across the top of the layers.
Whisk together all the dressing ingredients. Pour over the top of the salad, carefully spreading to the edges of the bowl.
I usually save a few tablespoons of some of the layers to make it pretty. A few grinds of black pepper add the perfect finishing touch.
Cover and refrigerate for up to 6 - 8 hours. Toss just before serving or let your guess spoon down through the layers.