In large skillet over medium heat sauté onions in oil until they start turning translucent, about 5 minutes. Stir in garlic and cook another minute. Stir in remaining ingredients and lightly simmer for another 5 minutes stirring occasionally. Remove from heat and strain sauce to remove seeds and chopped onions. Store in an air tight container in the refrigerator until ready to use.: The aroma of olive oil warming will be the first cue, followed by the gentle scent of softened onions as they become translucent and slightly sweet; you should hear a low, steady sizzle that is not frantic, and visually the pieces will go from opaque to glassy. This gentle sweating releases sugars that balance the berries, and it prevents raw onion bite. A common mistake is using too high heat, which makes the onions brown, adding an unwanted caramelized note. Keep the pan at medium and stir occasionally so the onions cook evenly.
Stir in garlic and cook another minute: Once the onions are translucent, adding the minced garlic releases an immediate, savory aroma; you will notice a vivid garlicky scent that brightens the base. Cook only about a minute until the garlic is fragrant and no longer raw, or it will turn bitter. The sound shifts to a slightly quicker sizzle as moisture from the garlic hits the warm oil. A common error is leaving the garlic in too long which causes a burnt, acrid flavor, so watch closely and stir to distribute heat.
Stir in remaining ingredients and lightly simmer for another 5 minutes stirring occasionally: When you add the chipotles in adobo , seedless raspberry jam , fresh raspberries , white vinegar , granulated sugar , and salt , the pan will erupt into a glossy, bubbling mixture. The jam will melt into the pan, and the fresh raspberries will burst, releasing bright juices. Keep the heat low enough that the mixture simmers gently, with soft bubbling rather than a rolling boil, allowing flavors to meld and the chipotle smokiness to infuse. Smell for a balance of sweet berry and smoky depth. A typical pitfall here is simmering too aggressively which can evaporate too much liquid and leave the sauce overly thick or scorched, so stir occasionally to prevent sticking.
Remove from heat and strain sauce to remove seeds and chopped onions: After simmering, the sauce will be aromatic, with a glossy sheen and a slightly reduced body. Removing it from heat prevents the residual warmth from overcooking the raspberries. Straining will give you a smooth, seed free texture and remove larger pieces of onions and chopped chipotle bits, leaving a silky finish that clings beautifully to food. Use a fine mesh strainer and press gently with a spatula; you will feel the thickened sauce yielding under pressure. One common mistake is skipping the strain and ending with a grainy texture, so if you prefer a refined sauce, take the time to strain properly.
Store in an air tight container in the refrigerator until ready to use: Once strained, transferring the sauce to an air tight container and chilling allows the flavors to rest and meld. The sauce will develop greater cohesion as it cools and the heat mellows slightly, the smoky notes integrating more fully with the fruit. Refrigerated, the sauce keeps well and is convenient for future use. A common oversight is using a container that is not sealed, which can lead to flavor loss or absorption of fridge odors, so choose a tight fitting jar and label it with the date.
