Hironaka's construction gives for any projective $3$-fold $X$ equipped with curves $C, C' \subset X$ intersecting transversally at two points $P, Q$ a birational modification $f : \tilde{X} \to X$ where $\tilde{X}$ is not projective (see Hartshorne appendix B).
However, we can choose $X$ such that it is,
(1) simply connected,
(2) has $h^{2,0} = h^{0,2}$ and,
(3) has a big divisor $D$ disjoint from $C, C'$ (which must not be ample)
Then
$$ H^0(\tilde{X}, \mathcal{O}_X(n f^* D)) = H^0(\tilde{X}, f^* \mathcal{O}_X(n D)) = H^0(X, \mathcal{O}_X(n D) \otimes f_* \mathcal{O}_{\tilde{X}}) \\ \supset H^0(X, \mathcal{O}_X(n D)) $$
and since $D$ is big, this grows as a degree $3$ polynomial.
Concretely, choose $X$ to be the blowup of $\mathbb{P}^3$ at a point $P \in \mathbb{P}^3$ and then the special fiber is $\mathbb{P}^2$ which indeed contains two suitable curves $C, C' \subset X$ and choose $D$ to be the pullback of an ample $\mathbb{P}^2 \subset \mathbb{P}^3$ which does not contain $P$.