Krishna is one who is pleased with even the smallest of food offerings. He was satisfied with the a single leftover leaf offered by Draupadi in the Mahabharata. Here is a mantra for offering prasadam to Krishna.
Krishna Karshthi Akarshati Sarvan Jivan Ithi Krishna
कृष्णा कर्षति आकर्षति सर्वान जीवान इति कृष्णः
Stories from Mahabharata, Srimad Bhagavad Purana, other Puranas and Harivamsa clearly suggests that what matter is unwavering devotion and following Dharma. Krishna is always there with one who is following the rules of nature.