Place the peppers, tomatoes, garlic and onion into a large roasting pan. Season with salt and pepper and place in a medium-hot wood oven to roast. Allow to cook, turning the peppers occasionally, until everything is very soft, approximately 15 to 20 minutes. The tomatoes and onions should be beginning to char around the edges and the skin of the peppers should be blackened all over. Remove from the oven and allow to cool.
Meanwhile, trim off the ends of the asparagus. If you are dealing with thick asparagus, you may want to peel the bottom third of each spear to remove the woody outer skin. Anything pencil-thickness or skinnier should be fine without peeling.
Place the almonds in a single layer in a saute pan and toast in your wood oven until fragrant, about 5-8 minutes depending on your oven temperature. Right before you’re ready to take the almonds out, add the ancho chili to the pan and allow it to toast for about 1 minute. It should darken in color slightly and puff up like a balloon. Remove the chili and almonds from oven.
When the bell peppers are cool enough to handle, peel off the skin and remove the stem and seeds. Peel the paper off the outside of the garlic cloves. Remove the stem and seeds from the ancho. Place the peppers, garlic and ancho in the carafe of a blender, along with the tomatoes, onion, almonds and sherry vinegar. Blend until incorporated, then, with the motor running, drizzle in the 3/4 cup of olive oil. Process until smooth. Taste and adjust the seasoning with salt and pepper.
To roast the asparagus, toss with the remaining 2 tablespoons of oil and salt and pepper to taste. Place in a large roasting pan big enough to hold the spears in a single layer. Place in a hot wood oven and roast, stirring occasionally, until the asparagus has begun to caramelize and is just cooked but still has a slight crunch when you bite into it, about 4-7 minutes.
Remove from the oven and top with the romesco. Give me a plate of this and a glass of albariño and I’m good to go, but if you’re looking for a complete meal, add a nice piece of roasted fish and some rice and you should be all set.