In a medium saucepan over medium heat, melt the butter.
Whisk in the flour, salt, pepper, onion powder, and garlic powder until smooth and bubbly.
Gradually whisk in the half-and-half and sugar. Continue whisking until the mixture thickens and begins to bubble.
Add the frozen peas, stirring to coat well.
Reduce heat to low and simmer for 8–10 minutes, or until the peas are tender and the sauce is creamy.
Taste and adjust seasoning if necessary. Serve warm.