Sure. You can try looking on fanfiction.net. There are often many original character (oc) paired with Black Widow stories there. Some might be about an oc being her partner in a mission, and they develop a deep bond over the course of the adventure.
One great place to find oc x black widow fanfiction is Archive of Our Own (AO3). There are various tags you can use to narrow down your search. For example, if you want a story where the oc is a super - powered individual like Black Widow, you can search for relevant tags. The stories there range from action - packed adventures to more emotional, character - study type fics.
Chapter 576, "The Electronic Pickles are Gone!", is the clearest early answer because it turns Jiang Li's situation into a concrete plot event. Early on, Tonight, Team Q exceptionally didn't cook.. By the end, Before Team Q arrived, they at least had fish to eat, but now even....
Chapter 600, "You merchants aren't even fit to carry my shoes!", is the clearest early answer because it turns Shen Ruobing's situation into a concrete plot event. Early on, Shen Ruobing was not deaf to the ironic tone in Jin Siyue's comments,....
Chapter 560, "These People Have Definitely Been Cursed!", is the clearest early answer because it turns Yu Li's situation into a concrete plot event.
Chapter 530, "I Only Drink 80 Degree Tea!", is the clearest early answer because it turns Degree Tea's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Old Sir Gu took a step back, his expression cold and guarded as he...
Chapter 653, "Everyone's Champion", is the clearest early answer because it turns Wilderness Survival's situation into a concrete plot event. It opens with As dawn broke, "Wilderness Survival 30 Days" released a notice on...
Chapter 453, "Secretly in Love with Jiang Yan", is the clearest early answer because the hidden truth stops feeling like mere subtext. Early on, On the cruise ship, Zheng Xun walked over with a mournful expression....
Chapter 471, "This is What Happens When You Abandon Sister Li!", is the clearest early answer because it turns Shining Transformation Trip's situation into a concrete plot event.
Chapter 621, "What Makes You Think I Would Save You?", is the clearest early answer because it turns Jiang Li's situation into a concrete plot event. It opens with The two walked for a long time before they reached a point where the...
Chapter 588, "Looking like this, he must be a male model in a bar!", is the clearest early answer because it turns Sister Li's situation into a concrete plot event. Early on, However, what they didn't expect was that Zhao Lang had actually....
Chapter 489, "Has She Been Morally Kidnapped?", is the clearest early answer because it turns Guan Xiong's situation into a concrete plot event. It opens with Yeah," Nina nodded, "I thought you looked pretty imposing, must be... and closes on However, Nina wasn't willing to give up just yet;