Picante sauce differs from salsa in heat, both in spiciness and cooking. Cooking concentrates the sugars in the tomatoes, and it gives picante sauce its smooth consistency and rich taste. You also can use spicier peppers in picante; slow cooking tempers their spicy edge and melds it into the overall flavor of the sauce. Picante follows a similar formula to salsa: Four parts tomatoes to one part sofrito. If you don't want the richness that comes from roasted fresh tomatoes, use canned tomatoes.
Start the oven broiler. Rinse and dry the tomatoes.
Cut out the tomato cores. Place the tomatoes in a dish or on a sheet pan lined with aluminum foil.
Broil the tomatoes until their skin blisters; rotate the tomatoes as soon as one side blisters. It takes about 5 or 6 minutes to roast the tomatoes under a preheated broiler.
Peel the skins off the tomatoes and let them cool to room temperature. If desired, cut the tomatoes in half crosswise and scoop out the seeds with a spoon. Deseeding the tomatoes makes the picante a bit sweeter, but it isn't necessary.
Roughly chop the tomatoes for rustic, chunky cause. Puree them for a smooth consistency. Set the tomatoes aside.
Add a tablespoon of olive oil to a heavy-bottomed saucepan. Add 1 part sofrito, or about 1/4 the amount of tomatoes. Sofrito, the Latin American equivalent of mirepoix, consists of 2 part chopped onions to 1 part each red and green bell peppers, along with minced garlic and cilantro to taste.
Saute the sofrito in the saucepan over medium heat until softened, about 5 or 6 minutes. Lower the heat to medium-low and add the tomatoes; give everything a good stir.
Add 1 or 2 deseeded chile peppers, sliced in half lengthwise. Using halved chile peppers -- and taking them out of the sauce later -- provides heat without bitterness and makes a smoother, balanced picante. You can use any chiles you like; jalapenos typically give light to moderate heat, and habaneros provide moderate to moderately high heat.
Cook the picante sauce until thickened, about 20 to 25 minutes, stirring frequently. Adjust the sauce as needed with vegetable stock or chicken stock, or use it as is. If you add stock, bring the sauce to a simmer and give everything a good stir.
Use the sauce as is or store it in an airtight container in the refrigerator up to 1 week.