Heat olive oil in a large pot over medium heat.
Sauté onions and garlic until soft and fragrant, about 5 minutes.
Add diced beets and vegetable broth; bring to a boil.
Reduce heat and simmer until beets are tender, about 30 minutes.
Use blender to puree soup until smooth; stir in lemon juice, salt, and pepper.
Whisk cornstarch into 1/2 cup almond milk until smooth.
Heat remaining almond milk, coffee, and sugar in saucepan until warm.
Slowly whisk in cornstarch mixture until pudding thickens (about 5 minutes).
Remove from heat, add vanilla, and cool slightly.
Serve warm beet soup followed by chilled coffee pudding.